Sascha Zverev was a point away from being two breaks down in the deciding set against one of the steadiest baseliners on the ATP World Tour, but the German teen did not give up. The wild card  fought through cramps, worked his way back into the match and downed third seed Gilles Simon 7-5, 3-6, 7-6(4) in just under three hours in Rotterdam on Thursday.

“The crowd helped me so much,” Zverev said. “I really had to give it all I’ve got. When I was cramping, my box was worried, but I fought hard and stayed in there. Gilles can run all day long so it was tough for me physically.”

The 18 year old, the youngest player in the draw, is into his second quarter-final is as many weeks. In Montpellier, he upset Marin Cilic in the second round en route to the semi-finals. The win against Simon improved his record against Top 20 players to 4-6.

Zverev’s quarter-final opponent will be fifth seed Gael Monfils, who eliminated 19-year-old Borna Coric on Wednesday. Zverev is currently No. 70 in the Emirates ATP Rankings and can overtake Coric, the youngest player in the Top 50 (No. 38), with a title in Rotterdam.

“We’ll see how I feel because right now I’m quite exhausted, but I am very happy to be in the quarter-finals.”

American No. 3 seed Donald Young is through to his first quarter-final of the season after downing Marcel Granollers 6-1, 7-6(2) at the Memphis Open on Thursday. The World No. 48 in the Emirates ATP Rankings dropped his opening serve before reeling off six games to take the first set, breaking serve three times en route. 

“It was good. Apart from the first game it was a really solid match,” Young said. “I was able to be aggressive and put some pressure on and not allow him to do the usual mix of shots that he likes to pull out.”

Players traded breaks of serve early in the second before games continued on serve until the tie-break. From there, it was all Young. Making his seventh appearance in the tournament, the 26 year old closed it out on his first match point and moved to within one win of matching his semi-final run from last year.

“This year, it’s the best I’ve played, even though I haven’t played many matches,” Young said. “I didn’t want to go three. Anything could happen in the third if he got momentum.”

He will face Ricardas Berankis next, after the Lithuanian upset Bosnian eighth seed Damir Dzumhur 6-3, 6-4. Berankis, World No. 102 in the Emirates ATP Rankings, had claimed the pair’s only prior clash in Brisbane two years ago and broke serve three times in the opening set.

The 25 year old broke Dzumhur’s serve to love to close out the match in one hour and 23 minutes. He will carry a 1-0 FedEx Head2Head record into his match against Young.

German Benjamin Becker overturned a 0-1 FedEx ATP Head2Head record against seventh-seeded Australian John Millman to register a 6-2, 7-6(6) victory.

The 34 year old progressed to the quarter-finals in one hour and 21 minutes. After Becker took the opening set without losing a point on his second serve, he quickly found himself trailing a break at 3-0 in the second. The German rallied to break back, however, and saved a set point in the second-set tie-break before closing out the win.

At age 33, David Ferrer is still going strong. The Spaniard, seeded second, routed Argentine wild card Renzo Olivo 6-2, 6-2 at the Argentina Open on Thursday to move into the quarter-finals. Ferrer needed only 72 minutes to advance.

In the speedy win over the World No. 151, the Javea native showed off his remarkable consistency against lower-ranked players. Last year, he only lost one ATP World Tour match on clay against a player ranked outside the Top 5 (Andujar, Barcelona SFs). Since turning pro in 2000, he has won more than 75 per cent of matches against opponents who trail him in the Emirates ATP Rankings.

Next up for the efficient Spaniard is eighth seed Pablo Cuevas, who saw off Santiago Giraldo 6-4, 6-2 in 85 minutes. Giraldo was looking for his first win over Cuevas since 2006, but was defeated after the Uruguayan broke him four times in nine opportunities.

Ferrer holds a 2-0 lead in his FedEx ATP Head2Head rivalry against Cuevas and has never dropped a set against his quarter-final opponent.

Viktor Troicki is one win away from equalling his best performance at the ABN AMRO World Tennis Tournament after knocking out Hyeon Chung, one of four teenagers in the Top 100 of the Emirates ATP Rankings, 7-6(5), 6-2 in 90 minutes to maintain his early season form.

The two-time Sydney champion, who also finished runner-up to Roberto Bautista Agut in last week’s Sofia final, now goes on to meet the oldest player in the draw, 34-year-old Nicolas Mahut, on Friday. Troicki is hoping to better his 2011 run to the Rotterdam semi-finals (l. to Soderling). Mahut overcame fellow Frenchman Jeremy Chardy 7-5, 6-2 in their fourth meeting.

“Today was a really tough match and I was fortunate to win the first set, saving three break points,” said Mahut. “I only had one and I got it. I was just focused on holding serve and I’m happy to go through. I feel great, but I know it’s going to be tough against Troicki, who I lost to in the Sydney quarter-finals [last month].”

Three-time champion Kei Nishikori got his bid for a fourth straight Memphis Open title under way on Wednesday with a 6-2, 7-5 triumph over American Ryan Harrison. The top seed extended his winning streak to 14 matches in Memphis with the one-hour, 21-minute result.

Nishikori had won the pair’s two prior FedEx ATP Head2Head meetings coming into the night clash, including a three-set affair at the same stage of last year’s tournament. After Harrison held his opening service game, the World No. 7 in the Emirates ATP Rankings put the pedal down, reeling off five games in a row, converting on two of three break points before the American could hold again. 

Nishikori secured the opening set on his first opportunity after 27 minutes before his 124^th-ranked opponent mounted a challenge late in the second. With Nishikori serving for the match at 5-4, Harrison converted his first break of the match on his fifth chance. He saved four match points in the process.

His joy was short-lived, however. Nishikori broke again for 6-5 and closed it out with a love hold on his fifth match point to move through to a quarter-final clash with Kazakhstan’s Mikhail Kukushkin, an earlier 6-1, 7-5 winner over No. 5 seed Denis Kudla.