AMELIA ISLAND, Fla. (AP) -- Arantxa Sanchez-Vicario pulled a stunner Friday, defeating top-seeded Martina Hingis 6-2, 6-4 at the Bausch & Lomb Championships for just her second victory in 17 tries against the world's top player.

The seventh-seeded Sanchez-Vicario forced Hingis into mistakes and advanced to the semifinals to play sixth-seeded Amelie Mauresmo.

``I think you learn from your previous mistakes,'' Sanchez-Vicario said. ``Obviously, she's been beating me. I had to be more aggressive, move her around and take more chances.''

She did that and more, forcing Hingis into looking for shortcuts -- like a handful of missed drop shots -- and frustrating the 20-year-old champion making her first appearance on the green clay of Amelia Island.

After Sanchez-Vicario hit a drop-shot winner early in the second set, Hingis slammed the ball into the ground, popping it over the net and onto the other end of the court. She slapped her racket on the net in frustration after the match, while Sanchez-Vicario pumped her fists and gestured to a crowd that has grown to adore her in her 12 appearances at Amelia.

``I think I surprised her,'' said Sanchez-Vicario, who hadn't won a set over Hingis in three years and hadn't beaten her since 1996, also on clay, at Hilton Head, S.C. ``I felt more comfortable on the court.''

A clay-court specialist, Sanchez-Vicario now might be considered the favorite, especially considering the rash of injuries that have broken out.

Third-seeded Elena Dementieva pulled out Friday, unable to play her quarterfinal against Mauresmo after tearing a tendon on the bottom of her foot in a third-round victory.

Dementieva needed crutches to depart the stadium Thursday after a 6-4, 6-2 victory over Elena Likhovtseva. Dementieva hurt herself while lunging for a shot that sealed the first set.

Before the tournament began, Monica Seles and Anna Kournikova pulled out with foot injuries. On Monday, Mary Pierce tweaked her back throwing a medicine ball, and she had to withdraw. Second-seeded Conchita Martinez lost her first match, leaving very few well-known names outside of Hingis and Sanchez-Vicario.

Fourth-seeded Amanda Coetzer is the highest-seeded player remaining in the draw, and the only player left in the field ranked in the top 10. Coetzer played 10th-seeded Meghann Shaughnessy later Friday.

The last quarterfinal, scheduled for Friday night, pitted a pair of unseeded players, Nadia Petrova and Silvia Farina Elia.