Martina Hingis and Venus Williams are headed for a quarterfinal showdown, setting up one of the most intriguing matches at the French Open.

But the other Williams sister, Serena, is out. Her game nosedived after a strong first set and she lost to Arantxa Sanchez Vicario 4-6, 7-5, 6-3.On the men's side, No. 3 seed Marcelo Rios was one step from regaining the top ranking. The Chilean moved into the quarters with a 4-6, 6-4, 6-3, 6-3 victory over Albert Costa of Spain. If he makes the semis, he'll oust Pete Sampras from the No. 1 spot.

While the American men have bombed at the French Open, the American women are doing just fine. Three advanced to the final eight Sunday.

Hingis, the top seed and world's No. 1 player, beat Anna Smashnova of Israel 6-1, 6-2. Still, Hingis said, "It wasn't as easy as I thought it was going to be."

Venus Williams reached the quarters with a 6-1, 6-3 victory over Henrieta Nagyova of Slovakia. Venus slammed seven aces to none for her opponent.

In a match between two of the game's headline players, she'll meet Hingis, the top seed and No. 1 player. Hingis beat Anna Smashnova of Israel 6-1, 6-2. Still, she said, "It wasn't as easy as I thought it was going to be."

Serena Williams, meanwhile, overpowered Sanchez Vicario early on with backhand winners. She surged to a 5-2 lead in the second set, but then could not seem to hit a good shot. Sanchez Vicario, the No. 4 seed from Spain, won five straight games to take the second set.

In the third set, Sanchez Vicario broke to lead 2-1, then broke again in the final game.

No. 2 seed Lindsay Davenport advanced with a 6-3, 4-6, 6-2 victory over Sandrine Testud of France.

And No. 6 Monica Seles completed the American trio in the quarters, easily beating Chanda Rubin, 6-1, 6-4. Patty Schnyder of Switzerland also advanced with a 6-1, 6-3 win over Magui Serna of Spain.

Former French Open champion Thomas Muster of Austria advanced to the quarters with a five-set win over Fernando Meligeni of Brazil, 6-4, 6-7 (8-6), 6-3, 3-6, 6-3.

In another five-setter, No. 14 seed Alex Corretja of Spain downed Hernan Gumy of Argentina 6-1, 5-7, 6-7 (4-7), 7-5, 9-7. The third-round match, which had been pushed back because of rain, took five and a half hours.

Reaching the quarters was No. 15 Felix Mantilla of Spain, who easily beat Ramon Delgado of Paraguay 6-2, 6-2, 6-4. Delgado ousted Sampras in the second round.

In yet another victory for Spain, No. 12 Carlos Moya made it to the quarters with a 6-3, 7-5, 3-6, 6-4 victory over Jens Knippschild of Germany.