By Richard Pagliaro | Friday, June 3, 2016

Samantha Stosur is a member of a very exclusive club. She's one of only four women to beat Serena Williams in a Grand Slam final.

Stosur believes Garbiñe Muguruza may be next.

More: Serena Beats Bertens, Will Meet Muguruza in Final

The fourth-seeded Spaniard overpowered the 2010 French Open finalist, 6-2, 6-4, to reach her first Roland Garros final.

Stosur, who upset Williams in the 2011 US Open final, says Muguruza has "a very good chance" to topple the world No. 1 in tomorrow's French Open final.

"Absolutely. Look, I do think she's got a very good chance to win tomorrow," Stosur said of Muguruza. " I think she's played well the whole tournament. I watched a little bit of Serena. I don't feel like she's in her best form at the moment.

"Having said that, she's still in a final and you certainly wouldn't ever count her out. I think Garbiñe is playing well enough to certainly have a really good chance."

Venus Williams (2001 US Open, 2008 Wimbledon), Maria Sharapova (2004 Wimbledon), Stosur (2011 US Open) and Angelique Kerber (2016 Australian Open) are the only women to defeat Serena in a Grand Slam final.

The reigning Roland Garros champion carries a 21-5 Grand Slam finals record into her fourth French Open final.

Since losing the 2011 Flushing Meadows final to Stosur, where she was forced to play the semifinals and final on back-to-back days, Williams has won eight of her last nine Grand Slam finals, including a 6-4, 6-4, victory over Muguruza in the Wimbledon final last July.

The 22-year-old Muguruza has breezed through 12 straight sets in reaching her second Grand Slam final in her last four majors. While the 34-year-old Williams has labored in her last two matches, rallying from a set down to fight off 60th-ranked Yulia Putintseva in the quarterfinals and saving two set points to subdue hobbled world No. 58 Kiki Bertens in the semifinals.

How will Williams' body hold up playing four days in a row while reportedly battling a strained abductor? And can the world No. 1 withstand the mental and emotional pressure knowing she is once again one win away from equaling Steffi Graf's Open Era record by collecting her 22nd Grand Slam title?

Williams saved two set points defeating Kiki Bertens in the semifinals. Asked if she is battling a strained abductor, Williams replied: "Yeah, I have had some issues, but, you know, it is what it is... I think it's survival of who can do best."

Playing first-strike tennis, Muguruza dealt the world No. 1 a crushing 6-2, 6-2, thrashing at the 2014 Roland Garros—Williams' last loss in Paris and her worst Grand Slam defeat—by driving the ball deep down the middle and denying her access to angles.

The 6' Spaniard is one of the few women in the world who can straddle the baseline and bang heavy strikes off both wings vs. Williams. Stosur suggests movement will be the key to a final played in slow conditions.

When healthy, Williams is a better mover than Muguruza. A core question: Will she be fit enough to create running rallies and can she play the sharp angles required to back Muguruza off the baseline?

Stosur says moving Muguruza and making the flat hitter strike on the stretch is a key to beating her on clay.

"(Muguruza is) obviously is a very good player," Stosur said. "She's had a great couple of years since she's got to the top of the game. She's stayed in the top 10 that whole time. So once you're there it's not easy to stay there, and I think matches like today and probably what she's played all week with her aggressive style is why she's there. If she's on, she's very hard to beat.

"But if you can kind of find little cracks and put her in positions of the court where she, you know, can't just hit the way she wants to, then I guess that's where you see what deficiency she has. But you've got to be able to find that, and when she's on that's difficult."