And then there were four. Who will be left standing in Paris for Saturday’s Roland Garros final? We preview today’s semifinal action right here on WTATennis.com.

Friday, Semifinals

[1] Serena Williams (USA #1) vs. Kiki Bertens (NED #58)
Head-to-head: Williams leads, 1-0
Key Stat: Bertens has won 12 matches in a row to reach her first Grand Slam semifinal.

Serena Williams has won 10 matches in a row. Kiki Bertens has won 12 matches in a row. Something will have to give on Friday as the tour’s two hottest players collide with a spot in Saturday’s final on the line in Paris. Bertens prolonged her magical run on Thursday when she defeated Timea Bacsinszky in straight sets to become the first Dutchwoman to reach the Roland Garros semifinals since 1971. But the 24-year-old will have to steady herself for one of the toughest challenges in tennis when she takes the court against top-seeded Serena Williams on Friday. Williams, arguably the best big-match player of all-time, owns a 26-4 record in Grand Slam semifinals and has won 12 of her last 13. Bertens, who hits an extremely heavy ball, will have to go big or go home against Williams. After suffering an injury to her left calf during the win over Bacsinszky, she’ll likely take a more aggressive approach against Williams, hoping to get the World No.1 on the run early and often. “I have some problems with my calf,” she admitted on Thursday. “I’m just gonna prepare again for tomorrow, do everything what I can with the physios, and we will see how it is.” Williams was disappointed with her effort against Yulia Putintseva in Thursday’s quarterfinal, and was quick to admit that fact in press. “I just was not playing my best,” Williams said. “I kept missing, just misfiring. Honestly, at one point I didn’t see the light at the end of the tunnel.” Williams scraped through the second set and then dominated the third in vintage fashion to advance. She knows she’ll need a more Williams-like effort to survive Bertens’ bullets on Friday. “Obviously she has a big serve and a big forehand,” Williams said. “She really moves the ball around well… I have to do something better and different if I’m going to stick around.”

Pick: Williams in two

[4] Garbiñe Muguruza (ESP #4) vs. [21] Samantha Stosur (AUS #24)
Head-to-head: Stosur leads, 1-0
Key Stat: Stosur owns a 2-2 record in Grand Slam semifinals

2010 Roland Garros runner-up Samantha Stosur has found her groove in Paris in what will be her last event with her longtime coach David Taylor in her box. Can the 32-year-old Aussie prolong Taylor’s coaching career for one more day? To do so she’ll have to get past a scorching-hot Spaniard who is looking more and more impressive with each passing round. Garbiñe Muguruza has won her last ten sets on the terre battue and is wearing the calm, collected expression of a champion in the making. Already a Wimbledon finalist, the Spaniard is hungry to prove that she’s an all-surface maven this weekend. Muguruza overcame a slow start to defeat Shelby Rogers in the quarterfinals on Wednesday, but is well aware that another slow start could mean the death of her dream in Paris. “I need to dictate play from the very beginning of the match,” Muguruza said afterwards. “I know that my opponent started in full swing; I shouldn’t wait for my opponent to dictate play.” Stosur hasn’t been this deep at a major since she reached the semis at Roland Garros in 2012, but the 32-year-old has demonstrated remarkable poise throughout the fortnight, weathering difficult conditions, a tricky draw and an injured left wrist to reach the final four. Now she knows the margins are thin and the intensity will be high, but it’s a challenge she appears more ready to accept than ever. “I probably have more belief in some ways now than what I did then,” Stosur said, referring to her lone Grand Slam title in 2011, after defeating Tsvetana Pironkova in the quarterfinals on Wednesday. “You don’t know if you can do that. Now I know I have done that. I know I can do it.”

Pick: Muguruza in three

Around the Grounds: The French duo of Kristina Mladenovic and Caroline Garcia is the highest-seeded team remaining in the doubles draw. The fifth seeds will take on Russia’s Margarita Gasparyan and Svetlana Kuznetsova for a spot in the doubles final on Friday. The other doubles semifinal will be contested by seventh-seeded Russians Ekaterina Makarova and Elena Vesnina and the unseeded Czech duo of Barbora Krejcikova and Katerina Siniakova.

By The Numbers

3 – Number of players to own more than three Roland Garros singles titles (Evert, 7, Graf, 6, Henin, 4).

26 – Williams has reached 26 major finals, compared to three for the other three semifinalists, combined.

27 – Bertens is projected to reach a career-high ranking of 27 as a result of her semifinal appearance in Paris. She could go as high as No.10 if she wins in the title.

1977 – The last time a Dutchwoman reached the semifinals of a major (Betty Stove, U.S. Open).

2 – Number of players born in the 1990’s remaining in the draw (Muguruza, Bertens). The only player born in the ’90s to have previously won a major is Petra Kvitova.

-Chris Oddo, wtatennis.com contributor