PARIS -- Serena Williams turns 40 in September, and no one knows how many more French Open appearances she will make, as this year's tournament ended for her on Sunday.
Williams fell way behind and could not put together a comeback against a much younger and less-experienced opponent in the fourth round at Roland Garros, losing 6-3, 7-5 to Elena Rybakina -- who wasn't even born when the American made her tournament debut in 1998.
Asked whether that might have been her last match at the clay-court major, Williams responded: "Yeah, I'm definitely not thinking about it at all. I'm definitely thinking just about other things, but not about that."
The next Grand Slam on the calendar is Wimbledon, which begins June 28.
"I'm kind of excited to switch surfaces," Williams said. "Historically I have done pretty well on grass."
Williams has won 23 Grand Slam singles titles, and coupled with 20-time Slam champ Roger Federer's withdrawal from the tournament Sunday, two of the sport's greatest and most popular players are done at the French Open. That's quite a blow to the tournament, its TV partners and tennis fans to see both gone from the field one after the other -- and a week after Naomi Osaka pulled out, citing a need for a mental health break.
Williams has won the French Open three times. But the American hasn't been past the fourth round in Paris since she was the runner-up in 2016.
Rybakina is a 21-year-old from Kazakhstan who is ranked 22nd. This was just the seventh Grand Slam appearance for Rybakina -- and the first time she ever made it so much as past the second round.
Against Williams, whose right thigh carried a heavy tape job, Rybakina hit big, flat serves. She dealt with, but managed to steady, her nerves. She even produced the occasional return winner off Williams' speedy and spectacularly gifted serve, breaking her five times, including in the next-to-last game.
"I am so happy with my match today. It was amazing," Rybakina said.
As for the final game, when she served out by far the biggest win of her nascent career, Rybakina said: "Of course I was nervous. I was not serving that well before. But I'm just happy that I just managed."
Every time Williams appeared as if she might turn things around, she could not quite get the momentum fully in her favor.
Down a quick break in the second set, she got to 2-all. Williams then was down 4-3 in the second set but pulled even again when Rybakina sailed a forehand well wide to get broken.
In the next game, Williams gave away the opening point when, near the baseline, she failed to get out of the way of a shot from Rybakina that was flying long. Williams smiled ruefully and leaned over, resting and propping herself up with her racket.
Repeatedly one sort of mistake or another undid Williams. She ended up with 19 unforced errors and only 15 winners.
"I'm so close. There is literally a point here, a point there, that could change the whole course of the match," Williams said. "I'm not winning those points. That, like, literally could just change everything."
Since winning the 2017 Australian Open while pregnant for her most recent major singles title -- No. 23 set a record for the professional era -- Williams has come close to tying Margaret Court's all-time mark of 24. That includes four runner-up finishes at Grand Slam tournaments, most recently against Bianca Andreescu at the 2019 US Open.
But since then, Williams has been beaten twice in semifinals, and once each in the third and fourth rounds. Last year at the French Open, she withdrew before the second round, citing an injured left Achilles.
Rybakina next will meet Anastasia Pavlyuchenkova with a semifinal berth on the line. Pavlyuchenkova advanced with a 5-7, 6-3, 6-2 victory over two-time Australian Open champion Victoria Azarenka.
The other quarterfinal on that side of the women's draw is going to be Paula Badosa against Tamara Zidansek. Neither has been this far at a major tournament, either.
One of those four players will become a first-time Grand Slam finalist next weekend.
Information from The Associated Press was used in this report.