Hingis outlasted Chanda Rubin 5-7, 7-5, 6-1 Wednesday night until Hingis' mental toughness prevailed.

The second-round match of the estyle.com Classic, played at the Manhattan Country Club, lasted 2 hours, 10 minutes. Last week at the Acura Classic near San Diego, Hingis lost in the quarterfinals to Amy Frazier.

``At first, I didn't play so well, but I was still in the game. Chanda made some mistakes, which Amy didn't do. After a loss like that, you lose confidence, so I was happy with what happened today,'' Hingis said. ``I had been playing up and down and I felt the momentum changed at 4-3 in the second. I don't believe in luck. I worked for it.''

Frazier plays her second-round match Thursday against seventh-seeded Arantxa Sanchez-Vicario of Spain.

Elsewhere Wednesday, fourth-seeded Conchita Martinez of Spain beat Alexandra Stevenson 6-4, 7-6 (2).

Martinez, the 1994 Wimbledon champion, overcame a 3-1 deficit in the first set and was down 4-1 in the second against the 19-year-old Stevenson.

``It's always hard to play someone for the first time,'' Martinez said. ``I got down because I wasn't aggressive. She hits the ball very hard. I wasn't passing well, then everything started to work.''

Defending champion Serena Williams, seeded fifth, also advanced to the quarterfinals, along with eighth-seeded Sandrine Testud of France.

Williams beat Thailand's Tamarine Tanasugarn 6 -2, 6-2, and Testud edged Belgium's Dominque Van Roost 6-2, 3-6, 7-5.

Williams needed 63 minutes to close out Tanasugarn after routing Romania's Ruxandra Dragomir in 38 minutes in the first round.