By Howard Fendrich
AP Tennis Writer

PARIS - As a past French Open champion, Jennifer Capriati is well-versed in the particular challenges the event and its slow, red clay present.

"You have to be fit to play any Grand Slam, but the whole mind-set is different here because it slows things down," the 2001 winner said. "You can't just blast anyone off the court. You really have to kind of work the point, work the rally, just be physically fit and have a lot of patience out there."

She struggled by No. 25 Elena Bovina 6-2, 3-6, 6-4 Saturday and was joined in the fourth round by Serena and Venus Williams, both straight-set winners.

Serena claimed the first eight games before letting her thoughts wander to what she'd eat for dinner, allowing Silvija Talaja to make a match of it.

But Serena composed herself long enough to overcome nine double-faults - "I predominantly don't hit nine doubles in a tournament, let alone a match," she sniffed - and win 6-0, 6-4.

Her older sister wasn't challenged during a 6-3, 6-1 victory over 2000 champion Mary Pierce.

On Sunday, Venus plays Australian Open semifinalist Fabiola Zuluaga of Colombia, while Capriati gets No. 17 Francesca Schiavone of Italy, and Serena faces Shinobu Asagoe of Japan, who acknowledged she didn't realize she won't get a day off, "because I've never been this far" at a major.

Sunday's other matches to determine the women's quarterfinalists are: No. 3 Amelie Mauresmo vs. No. 21 Magdalena Maleeva, No. 5 Lindsay Davenport vs. No. 9 Elena Dementieva, No. 6 Anastasia Myskina vs. No. 11 Svetlana Kuznetsova, No. 18 Maria Sharapova vs. Marlene Weingartner, and No. 14 Paola Suarez vs. Zheng Jie.

Capriati has always been coached by her father, Stefano, but she recently began working with Heinz Gunthardt, who was Steffi Graf's coach late in her career.

On Saturday, Capriati was asked what advice she would give if the Williams sisters asked her about hiring a coach from outside the family. Venus and Serena were taught how to play by their father and now are often accompanied to tournaments by their mother.

"I would just say, 'Go for it,"' Capriati said. "You're the one that's basically doing it all out there, and you're going to have to pay the price. You don't want to look back and have any regrets. ... If your parents love you, they'll be very supportive."

Highlights

Men's seeded winners: No. 8 David Nalbandian, No. 12 Lleyton Hewitt, No. 20 Marat Safin, No. 23 Feliciano Lopez, No. 28 Gustavo Kuerten.

Men's seeded losers: No. 1 Roger Federer, No. 19 Martin Verkerk.

Women's seeded winners: No. 2 Serena Williams, No. 4 Venus Williams, No. 6 Anastasia Myskina, No. 7 Jennifer Capriati, No. 11 Svetlana Kuznetsova, No. 17 Francesca Schiavone.

Women's seeded losers: No. 25

Elena Bovina.