Williams, who reached the final at Roland Garros in 2002 but missed the last two Grand Slam tournaments because of injuries, also lost to Jankovic in the third round at Wimbledon last year.

"I got a little bit tired at the end," Williams said. "It's tough on clay."

Top-ranked Roger Federer had no problems moving into the fourth round, winning the final nine games of his 6-2, 6-3, 6-0 victory over Potito Starace of Italy.

"It's difficult for everybody here at the moment with the conditions changing, the gusty winds and the cool conditions," said Federer, whose first-round match was played over two days because of rain. "So I'm happy to have put myself in the position of the fourth round already."

The 22-year-old Jankovic dominated the five-time major champion in the first set, winning 20 of the 24 points played in her service games, including the first 10.

"I never had it in my mind that I was going to lose the match," said Jankovic, who won a clay-court warmup tournament in Rome last month to make her one of the favorites heading into the French Open.

Williams recovered in the second set, jumping out to 3-0 lead and holding on by breaking Jankovic in the 10th game to even the match. But Jankovic, who reached the semifinals at the 2006 U.S. Open, broke Williams three times in the third set.

"The third set went a little bit faster than what I expected," Williams said. "I felt a little bit slow ... I couldn't get my feet where I wanted them."

Federer, bidding for a fourth consecutive Grand Slam title, next faces No. 13 Mikhail Youzhny of Russia. Youzhny, a semifinalist at last year's U.S. Open, beat 2003 French Open champion Juan Carlos Ferrero 6-7 (3), 7-6 (3), 6-2, 6-2.

"I think he's a fantastic player," Federer said of the Russian. "I have to definitely be careful, even though I've never lost against him."

Igor Andreev of Russia, who upset third-seeded Andy Roddick in the first round, advanced to the third round by beating Nicolas Massu of Chile 6-3, 3-6, 6-3, 7-5.

No. 6 Nicole Vaidisova of the Czech Republic reached the fourth round by beating 27th-seeded Samantha Stosur of Australia 6-4, 6-4.

Also, No. 20 Sybille Bammer of Austria beat 16th-seeded Li Na of China 6-4, 6-3, while No. 12 Daniela Hantuchova of Slovakia and No. 19 Tathiana Garbin of Italy also advanced.

Garbin reached the fourth round by beating Stephanie Cohen-Aloro of France 6-3, 6-0, and Hantuchova got to the third round by defeating Olga Poutchkova of Russia 7-6 (6), 6-3.

Serena Williams, Venus' sister who plays later today, is the only American left playing singles in Paris.

"She's playing great tennis, and she plays well in a crunch," Venus Williams said. "And I think the longer she's in the tournament, the better she'll play."

Yesterday, the rain came at just the right time for Amelie Mauresmo.

After easily winning the first set in her second-round match against Nathalie Dechy, Mauresmo struggled and was forced into a tiebreaker.

But, luckily for the fifth-seeded player, rain delayed play for nearly two hours, allowing the Frenchwoman to regroup and eventually earn a 6-3, 6-7 (3), 6-1 win.

"I came back much better ... really being able to play, and to play the game I know how to play," Mauresmo said.