Serena Williams, Danielle Collins setting up for all-American clash in French Open

The four women who have beaten Serena Williams in major finals since she returned from childbirth are no longer in Paris for the French Open. Simona Halep pulled out because of injury before the tournament got underway. Angelique Kerber and Bianca Andreescu were upset in the first round. Naomi Osaka withdrew following controversy over media obligations.

There were moments on Wednesday when it looked as if Williams might join that ever-growing list of early exits. There were flashes of vulnerability and listlessness in her second-round match against Mihaela Buzarnescu, and she needed over two hours and three sets to close out the match for a 6-3, 5-7, 6-1 victory.

Williams nearly fell to her feet on the final point of the second set -- Buzarnescu had her scrambling all over the court in a 14-shot rally. As Williams walked back to her chair in frustration, it was unclear if she had anything left for the decider.

But in the third set, she showed her dream of tying Margaret Court's record of 24 Grand Slam titles was still alive, no matter what had happened earlier in the match, her 1-2 record on clay leading into the event or her recent losses in Melbourne or New York.

"I knew going into the third, I just had to zero in on those important points," Williams said. "If I could just take those, it would be an easier time for me."

She did just that. The 39-year-old dominated -- winning 15 of 24 receiving points and edging her opponent in the longer rallies, including one in the third game lasting 19 shots and resulting in both players laughing after Williams finally won the point.

After that point, Williams was nearly unstoppable. When asked about it on court after the match, she laughed again and said the rally, and the match, had been "kind of fun."

After withdrawing because of an Achilles' injury prior to her second-round match in 2020, Williams now looks to reach the fourth round for the first time since her return in 2018. She is the lone remaining French Open champion on her side of the draw, and she is the second-highest-ranked player behind Aryna Sabalenka, whom she could potentially meet in the quarterfinals.

She'll have to get through Danielle Collins first, though, and Collins has other plans.

It's Collins' first tournament back since the Miami Open in March. She underwent surgery for endometriosis shortly after and revealed a cyst the size of a tennis ball was removed from an ovary during the procedure. After intensive rehabilitation and a gradual return to the practice court, the 27-year-old said she feels pain-free for the first time in years.

"I feel like this is the fittest I've been," Collins said during an interview on the Tennis Channel.

Collins has been public about the struggles she's had with endometriosis, a disorder in which tissue that normally lines the uterus grows outside of it. In a candid interview with the Telegraph last month, she described in detail the immense discomfort it has caused in her back and stomach, including an episode at Wimbledon in 2018, in which she was in so much pain, she was unable to stand on her own and needed a cart to transport her. Back pain also caused her to retire from her quarterfinal match against Iga Swiatek in Adelaide in February. She believed it was a slipped disc but later discovered it had been the cyst pressing up against a spinal nerve.

Collins described the improvement she now notices since the procedure in a news conference earlier this week.

"It's been really kind of shocking -- since surgery, I've just felt so much better, especially with my back pain," Collins said. "Like I'm not having any type of sciatic nerve pain, which I was dealing with for a couple of years. ... So now I'm just kind of relieved to just be feeling good consistently and not having to always track and be like, 'Oh, like is this going to be a bad week, do I have to kind of prepare my training around that or my tournaments around that?'

"It's just been a real weight that's been lifted off my shoulders since having the surgery, because I kind of just in some ways got used to [the pain] and kind of thought that that was normal to be dealing with."

Despite whatever pain she may have been feeling during her last stay in Paris, Collins reached the quarterfinals at the French Open in 2020. She upset 2016 Roland Garros champion Garbine Muguruza in the third round and held off Ons Jabeur in a memorable round of 16 clash before ultimately falling to eventual finalist Sofia Kenin.

Encouraged by the support she has received from women and hoping to empower others in similar situations, a rejuvenated Collins is showcasing some of her best tennis.

Playing against Anhelina Kalinina, who beat her in both of their previous meetings, Collins was nearly flawless in this second-round match. She needed just over an hour to record a 6-0, 6-2 victory.

Her performance impressed those who are most familiar with her game, but it wasn't a surprise.

"When you're coming back, you don't put a lot of expectations on yourself, but what's different about Danielle is she is one of the toughest competitors you'll ever see," said Martin Blackman, the general manager of player development for the USTA. "When she steps on the court, it means she believes she's 100 percent and is ready to play to win. She was moving well, she was playing very aggressive tennis, but not overly so, and was still respecting the surface, and played so well. Sometimes it takes a few tournaments to really feel like you're back at 100 percent physically, mentally and emotionally, but if today is any indication, she's already back to playing great tennis again."

Both Williams and Collins know what it takes to reach the second week in Paris, and they will have to raise the bar even more during Friday's all-American clash.

They have faced each other just once -- in the quarterfinals of the Yarra Valley Classic earlier this year. Williams won the fiercely contested battle 6-2, 4-6, 10-6, but it was clear her respect and admiration for her upcoming opponent extended far off the tennis court.

"I played her in Australia, actually. She plays well, especially when it's time to play, which is I guess all the time," Williams said. "She's also a really awesome person off the court.

"I love seeing her in the locker room. Ideally, it would be great if we didn't have to play each other, because I always want her to do super well."