When Novak Djokovic won the US Open for a third time on Sunday, he regained his place as his sport’s biggest ever on-court earner.

That is despite winning fewer Grand Slams – the most lucrative tournaments in tennis – and fewer ATP Tour titles than Swiss great Roger Federer.

The pair were set to meet in a quarter-final at Flushing Meadows, only for Federer to be stunned by Australian John Millman in the last 16.

And by beating Argentine third seed Juan Martin del Potro 6-3 7-6 (7-4) 6-3 in the final, the 31-year-old Serb overtook Federer in terms of career prize money – although as we will see, he still has a long way to go to catch the Swiss when it comes to off-court earnings.

How much have they earned?

Federer’s haul of 20 Grand Slam titles is more than any other man in history – six more than Djokovic, who only also trails Rafael Nadal and Pete Sampras in terms of major wins.

In total Federer has won 98 career titles, dwarfing Djokovic’s tally of 71.

However, there is not as much disparity between them when it comes to career prize money.

In terms of money earned solely from ATP singles and doubles matches, Federer had won £90.1m ($117,507,812) going into the US Open – slightly ahead of Djokovic’s total of £89.2m ($115,310,890).

Going out in the last 16 put another £205,000 ($266,000) into Federer’s account and, with £2.94m ($3.8m) going to the men’s champion at Flushing Meadows, Djokovic moved back above him for only a second time with victory over 2009 champion Del Potro on Sunday.

“Federer might have been doing it for over 20 years but Djokovic’s peak has been so recent when the prize has gotten so big,” explains Kurt Badenhausen, senior editor at Forbes magazine.

Why has Djokovic earned more?

So with Djokovic having won fewer Grand Slams – the biggest earner for any tennis player – and fewer ATP Tour titles, how has he managed to take home more cash?

The Grand Slams and ATP Tour have grown considerably in terms of global popularity, appeal and reach – and therefore money – over the past decade.

“The players have played a key role in driving that growth,” ATP spokesman Simon Higson said.

“The sport has seen significant increases in prize money levels over the past 10 years which have seen the players share in the overall commercial growth in the sport.”

One player has benefited more than most.

Djokovic has won 13 of his 14 Grand Slam titles since 2010, when the prize money for the champion moved past the £1m mark at all four majors.

Those prizes have continued to rise rapidly. Djokovic took full advantage between 2011 and 2016, winning 11 of 22 Slams and reaching seven other finals. Federer won just one major over the same five-year period.

Modern-day players rewarded by Tour growth

While the Slams continue to provide the biggest pay days for the world’s best players, the growth of the ATP Tour has also been key to Djokovic and Federer breaking the £100m figure.

Djokovic was the first player to pass that mark in 2016, with Federer then overtaking him thanks to his renaissance as the Serb’s form slumped.

An all-time record 4.7m fans watched ATP tournaments in 2017. And as audiences have increased, so have player earnings; ATP prize money – for tournaments excluding the Slams – has risen by 286% over the past three decades. Inflation over the same period is 92.8%.

From an annual total of $34.8m (£26.9m) distributed in 1990, prize money has climbed to more than $135m (£104m) in 2018.

No wonder the ‘Big Four’ of Federer, Djokovic, Nadal and Britain’s Andy Murray are the top-earning players of all-time.

In addition, players such as Spain’s David Ferrer and Czech Tomas Berdych, both mainstays in the world top 10 for years without winning a Grand Slam, have earned comparable amounts to global mega-stars of the previous era in Andre Agassi and Boris Becker.

Yet the same riches are still not on offer for their female counterparts.

Serena Williams, who lost to Naomi Osaka in Saturday’s women’s final when going for a record-equalling 24th Grand Slam title, has earned far less than Djokovic and Federer.

Before this tournament, the 36-year-old American had earned £66m ($86m) in prize money over her illustrious career – more than double that of older sister Venus, who is second on the list of all-time female earners.

Although parity was eventually achieved at Wimbledon when both singles’ champions were given the same winning cheque in 2007, the WTA Tour’s overall prize money still trails that of the ATP.

Federer’s overall wealth on a different scale

While Djokovic might be competing toe-to-toe with Federer on the tennis court, both physically and financially, he is nowhere near matching the Swiss’ overall wealth.

Federer is the 15th-richest sports person in history, having earned £522m ($675m) over his 20-year career. In 2017, his total income was £59.5m ($77m) – £50.3m ($65m) through endorsements and £9.2m ($12m) in prize money.

By contrast, Djokovic has an overall wealth of £135.4m ($175m) and brought in £18.2m ($23.5m) – £17m ($22m) through endorsements and £1.2m ($1.5m) in prize money – last year.

“Federer’s endorsement portfolio is unparalleled across all the sports,” explains Kurt Badenhausen, a senior editor at Forbes magazine specialising in the business of sport. “And many of these deals have struck out for 10-plus years.”

Why is Federer more attractive to sponsors than Djokovic?

Being considered the greatest man to grace a tennis court is clearly key.

“He has got a few things going for him,” Badenhausen says.

“One, he plays a global sport. Two, he’s been at the top of his game for a very long time. Three, the demographics of tennis are incredible in terms of disposable incomes and people who are ready to spend money on watches, cars and equipment.

“That’s why you have marketers banging down doors to get into business with Roger Federer.”

This has been illustrated by the Swiss, who has refused to acknowledge the word ‘retirement’ but knows the end is not far away, signing a 10-year deal with Japanese clothing company Uniqlo – worth £232m ($300m) – after his contract with long-time backers Nike expired.

Federer was as synonymous with Nike as Michael Jordan, Tiger Woods and LeBron James.

“Nike has traditionally paid top dollar for athletes that are still performing and still competing, but as those athletes moving towards retirement it is not necessarily willing to commit significant resources to those athletes,” Badenhausen explains.

What Federer intends to do post-playing has not yet been revealed publicly.

One would imagine more time would be devoted to the Roger Federer Foundation, which supports educational projects in Africa and Switzerland, along with a management company – set up alongside his long-time agent Tony Godsick in 2013 – that boasts Del Potro and Grigor Dimitrov in its ranks.

“To some degree Federer leaving Nike sent shockwaves after 20-plus years together, but as he moves into the next phase of his life it makes sense,” Badenhausen says.

“Federer’s popularity in Asia is off the charts so he looked at it as an opportunity where he can connect with his fans.

“With the Olympics in Tokyo in 2020 and Uniqlo being a big backer that could present a lot of synergy for Federer.”

Why is Djokovic not on same level?

One of the greatest tennis players of all time, plenty of charisma and portraying an image as a doting father, Djokovic has plenty going for him.

So why is he unable to reach the same heights commercially as Federer?

Badenhausen thinks there are two main factors: the country of his birth and not having a long-term partnership with sportswear brand like Federer had with Nike.

“His home country certainly has an impact, he is not going to get any deals from there,” he says.

“Federer has a lot of global deals but also has several very lucrative deals from big Swiss companies. That isn’t an option for Djokovic in Serbia.

“Also Djokovic has bounced around from one apparel brand to another. That has hurt him, without those brands breaking through.

“Federer has always had Nike at his back, marketing Federer around the world – and there is something to be said for the power of Nike.

“They have a long history of creating these personas that are bigger than life.

“They did it with LeBron James, Tiger Woods, Michael Jordan and in tennis with John McEnroe, who wasn’t the most successful of his generation but he was the biggest player of his generation because of the way Nike marketed him as the bad boy of tennis.

“Nike always pushed Federer as this graceful champion of the sport. Djokovic hasn’t had that backing.”

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Novak Djokovic produced an impeccable performance to beat Juan Martin del Potro in the US Open final and win his 14th Grand Slam title.

The 31-year-old Serb won 6-3 7-6 (7-4) 6-3 to earn his third triumph in New York and equal American great Pete Sampras’ haul of major trophies.

Djokovic, who won Wimbledon in July, will climb to fourth in the world after back-to-back Grand Slam victories.

Only great rivals Roger Federer (20) and Rafael Nadal (17) have won more.

Argentine third seed Del Potro, 29, was playing his first Grand Slam final since winning the 2009 US Open, having almost quit the game in 2015 because of multiple wrist injures.

A fairytale finish at Flushing Meadows was not to be, however, as former world number one Djokovic’s quality shone through.

Djokovic is one of only eight men to win the Wimbledon-US Open double and has now accomplished that feat for a second time.

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The Serb walloped a forehand volley to safety on his first match point, dropping to the floor and spreading out on his back with his arms and legs outstretched in celebration.

After hugging his great friend at the net, Djokovic jumped into his box to celebrate with his wife Jelena and team. Del Potro broke down in uncontrollable tears on his chair.

“It is not easy to speak right now,” Del Potro said on court.

“I’m sad because I lose but I’m happy for Novak.”

After the controversy surrounding Serena Williams’ defeat by Naomi Osaka in Saturday’s women’s final, a high quality match between two of the top male players ensured tennis was once again the talking point.

Djokovic continues renaissance to blunt Del Potro

Djokovic had a barren spell between winning the 2016 French Open, where he completed the career Grand Slam, and his fourth triumph at Wimbledon in the summer.

Struggling physically with an elbow injury and seemingly suffering mentally after what he described as “personal problems”, he went eight Slams without reaching the semi-finals until Wimbledon.

His performances at the All England Club indicated he was back close to his best and he has shown the same shot-making, stamina and steeliness at Flushing Meadows.

Djokovic had not faced a big server like Del Potro in his run to the final and showed all of his remarkable retrieving skills to frustrate his opponent.

Before the final, Del Potro had seen 41% of his serves unreturned in the tournament.

That figure dropped to 17% in the first set as Djokovic wore him down in some long rallies.

Djokovic had not threatened Del Potro’s serve until the eighth game of the match, clinically taking his only break point as the Argentine buckled first.

Djokovic keeps pro-Del Potro crowd quiet

Del Potro has a fervent support at the US Open and was backed by a noisy support as thousands of Argentine fans descended on the Arthur Ashe Stadium wearing their national colours of light blue and white.

It made for a partisan atmosphere in the biggest tennis stadium in the world and, with the roof closed because of rain, led to a cauldron of noise.

At times it resembled a football match rather than a tennis match.

Djokovic occasionally seemed annoyed by the support with the noise as British umpire Alison Hughes had to constantly plead with the crowd to remain quiet during points.

The atmosphere ignited again in the second set when Del Potro broke back to level at 3-3, before Djokovic silenced them with a courageous hold – after a 20-minute game lasting 22 points and in which he saved three break points to level at 4-4.

That proved to be the key moment in the match.

It enabled Djokovic to go on and take the second-set tie-break following four unforced errors from Del Potro’s forehand – including one on set point.

From that point a Djokovic victory looked inevitable and, after Del Potro wiped out a final-set break at 3-1 in the following game, the Argentine produced a double fault to give Djokovic another chance for a 5-3 lead.

Trying to force the issue, he hammered a backhand wide and Djokovic broke before serving out for victory.

Despite defeat, world number three Del Potro remained proud after an achievement he never thought would have been possible during his injury hell.

“I never gave up when I had the wrist problems,” he said.

“I got here to the final after nine years which is amazing because this is my favourite tournament on tour.”

Analysis

BBC tennis correspondent Russell Fuller

It was after watching Pete Sampras win Wimbledon – while sitting in his parents’ pizza parlour as a six-year-old – that Djokovic decided tennis was the sport for him.

He has rarely looked so ecstatic in his moment of victory: falling on to his back on the same court where his idol won his 14th and final Grand Slam 16 years ago.

Djokovic won with his customary elastic defence, and regular forays to the net. He was just a little better than Del Potro at the key moments – especially in a 95-minute second set, where he saved three break points in an eighth game which stretched to eight deuces and 20 minutes.

This time last year Djokovic was injured and uncertain about his future direction. Six months away from the Tour helped him rediscover his motivation and appreciate just why he wanted to continue.

He has been the dominant player of the summer and could now end the year as the world number one. It has been a remarkable turnaround from a man who now threatens to dominate the men’s game once more.

Britain’s Alfie Hewett won the US Open men’s singles wheelchair title to lift his second Grand Slam trophy in as many days.

Hewett beat Japanese top seed Shingo Kunieda 6-3 7-5 on Louis Armstrong Stadium.

The 20-year-old also won the men’s doubles event alongside fellow Briton Gordon Reid on Saturday.

“I felt like I’ve been playing my best tennis this week and last week,” he said.

It is Hewett’s seventh Grand Slam win in total and follows his singles win at the French Open in 2017.

“I’m very excited. I didn’t really know what to expect today. Shingo’s obviously such a great player,” Hewett added.

“There’s something here that’s really clicking for me and I need to put my finger on it and take it into the other Slams.”

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Sue Barker believes “tennis was the loser” in a controversial US Open final – but said Serena Williams had a point when she criticised the umpire.

A series of incidents, which included the beaten American calling Carlos Ramos a “liar” and a “thief”, saw Williams penalised twice.

Afterwards the American said it was “sexist” to have been penalised a game.

“The umpire was following the rules by the book but Serena has a point,” said BBC Sport tennis presenter Barker.

Williams, who was beaten 6-2 6-4 by Naomi Osaka in New York, was given a code violation for coaching, followed by a penalty point for racquet abuse and finally a game penalty after accusing the umpire of lying.

“I’ve sat courtside watching the men ranting at umpires and they haven’t been given a violation,” added former French Open champion and world number three Barker.

“The fact that it was to be a game violation then robbed the crowd of what potentially could’ve been a third set.”

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Williams, who was aiming to equal Margaret Court’s record of 24 Grand Slam singles titles, refused to shake hands with umpire Ramos after the match.

She later accused him of sexism, saying: “He’s never taken a game from a man because they said ‘thief’.”

“Both have a point – Serena saying the male players can say what they want to umpires,” added Barker, who was speaking to BBC Radio 5 live’s Sportsweek programme.

“Earlier in the tournament we saw Alize Cornet being given a code violation for changing her shirt on court and then in the same tournament Mohamed Lahyani gets down from his chair to talk to Nick Kyrgios and persuade him not to give up on a match.

“He [Ramos] was following the rules by the book but sometimes the book has to be rewritten.

“You can’t have one rule for some players and some umpires don’t adhere to it and allow players to get away with things. They’ve just got to be fair to the players.

“Tennis was the loser and we lost what was potentially a fantastic match.

“I’ve never seen anything like it since I have been watching tennis. It was sad for the game.”

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What happened?

Williams was given a first code violation after Ramos judged a gesture from coach Patrick Mouratoglou to be coaching.

She said she had not received any tactics from Mouratoglou, telling the umpire she would “never cheat to win and would rather lose”.

The Frenchman later admitted that he had been coaching from the box but that Williams had not seen him doing so.

Williams then received another code violation for a racquet smash at 3-2 in the second set, leading to Ramos docking her a point.

With Osaka leading 4-3, Williams told the umpire: “You are a liar. You will never be on a court of mine as long as you live. When are you going to give me my apology? Say you are sorry.”

That led to Ramos docking her the next game to leave Osaka just one game away from victory at 5-3 up.

Williams refused to take to the court and demanded an intervention from the tournament referee.

Eventually she returned to the baseline, serving out a game to love before Osaka held serve to win her first Grand Slam win.

In her post-match news conference Williams said she was she “was not being coached” and that she “did not understand” why Mouratoglou would say he was doing so.

American 12-time Grand Slam singles champion Bille Jean King, one of the founders of the Women’s Tennis Association (WTA), backed Williams, saying: “When a woman is emotional, she’s ‘hysterical’ and she’s penalised for it. When a man does the same, he’s ‘outspoken’ and there are no repercussions.

“Thank you, Serena Williams, for calling out this double standard. More voices are needed to do the same.”

‘I feel so sorry for Naomi Osaka’

At the end of the match, security staff ran on to the perimeter of the court as Ramos walked off and the Portuguese did not return, as he would usually have done, for the trophy presentation.

Osaka, who describes Williams as her idol, pulled her visor down over her eyes to hide her tears when there was booing from the 24,000 crowd in the Arthur Ashe Stadium prior to the Japanese player being given the trophy.

The jeers were not aimed at her, with the fans instead expressing a sense of injustice at the way home favourite Williams had been treated.

The American appealed for calm in her runners-up speech, asking her supporters to “give credit” to Osaka’s achievement, and the winner was then applauded.

“I’m immensely disappointed,” said Barker. “I was so looking forward to what was going to be a fantastic finale to what has been an incredible tournament and it was all just taken away by Serena and the umpire. I feel so sorry for Naomi Osaka.

“Her first Grand Slam win has been marred in some way. She couldn’t celebrate in the way she wanted to.

“She is one of the most exciting players on the tour. It was just so sad for me to see at the presentation that she was in tears. They weren’t tears of joy.

“The crowd was booing and this was her moment. That’s not the way you want to celebrate your first Grand Slam victory and it was just sad for the sport to see it.”

What are the rules?

According to ITF Grand Slam rules:

• Verbal abuse is defined as a statement about an official, opponent, sponsor, spectator or other person that implies dishonesty or is derogatory, insulting or otherwise.

• Abuse of racquets or equipment is defined as intentionally, dangerously and violently destroying or damaging racquets.

• Players shall not receive coaching during a match (including the warm-up). Communications of any kind, audible or visible, between a player and a coach may be construed as coaching.

Should they be changed?

“It’s weird in the women’s game where they have coaching,” said Barker.

“For all the tournaments, bar the Grand Slams, coaches can come onto the court at the change of ends to speak to their players.

“I was against that. It’s a gladiatorial sport, it’s one against one – you work out how to do it.

“But, if it’s coming to things like this, it is ruining the game and it was just such a disappointing way for the tournament to end.

“If they can’t adhere to the rules then they will have to allow the coaching because we can’t have things like this outburst anymore. It is not good for the game.”

She added: “There can’t be a grey area any more. Maybe there has to be a supervisor that comes on and has the final say before you give a game away.”