By Jocelyn Noveck
Associated Press Writer
Sunday, May 31, 1998; 2:04 p.m. EDT

PARIS — 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.

Marcelo Rios could become No. 1 again with a quarterfinal victory. (AFP Photo)

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.

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.