CARLSBAD, Calif. (AP) - Martina Hingis lost just seven points on her serve in the second set and beat Dominique Van Roost 6-2, 6-4 on Thursday in the quarterfinals of the TIG Classic.

Hingis broke Van Roost twice in rolling through the first set in 31 minutes.

``I played very well and focused from the beginning,'' she said. ``Those games I won easily, I never struggled on my serve. I picked up on my game a little more.''

Hingis, the No. 2 seed, advanced to a semifinal against the winner of Friday's match between seventh-seeded Amanda Coetzer and Amy Frazier.

Other quarterfinal pairings Friday are top-seeded Lindsay Davenport against qualifier Anke Huber and fourth-seeded Venus Williams against Sandrine Testud, who defeated No. 6 Aranxta Sanchez-Vicario 6-2, 7-5 in the night match.

``I knew that she could come back. She had many chances,'' Testud said. ``What made the difference at the end was that I played the big points better.''

Testud, a Frenchwoman ranked 14th, won 11 of the last 12 points, including breaking Sanchez-Vicario at love in the 11th game. Testud is in the quarterfinals for the second straight week, having lost to Coetzer last week at Stanford.

``I was not aggressive last week,'' she said. ``I wanted to make sure that I was aggressive against Aranxta. I just wanted to go for the shots.''

Sanchez-Vicario converted just one of 11 break points in the 11/2-hour match. Her only title this year was at Cairo in April.

Van Roost, a Belgian ranked 15th in the world, pressed Hingis throughout the second set. In the fifth game, she had three chances to win before netting a forehand after the fourth deuce to set up a break point for Hingis. Van Roost then hit a smash long to trail 3-2.

Van Roost held serve after two deuces to trail 5-4, but Hingis won on the second match point when Van Roost's forehand service return went wide.

Hingis, the world's No. 2 player, is in her first tournament since being knocked out in the first round of Wimbledon a month ago. Coetzer is the only seeded player left in Hingis' half of the draw after fifth-seeded Mary Pierce lost in the first round and No. 3 seed Steffi Graf retired with an injury from a second-round match.

``It feels better being in the semis again,'' Hingis said. ``At Wimbledon, I don't know what I was doing.''

The crowd at the La Costa Resort and Spa backed Van Roost, and booed when line calls went against her in the second set. One fan yelled, ``Go home, Martina.''

``I have nothing to say against the crowd,'' Hingis said. ``They want to see you out there and play good tennis and be just the way you are. Not being like always moody or something.''

In a second-round match, Huber outlasted Barbara Schett of Austria 5-7, 6-4, 6-4. Huber got into the main draw through qualifying, the first time she had to do so since 1990.

``I was thinking a long time if I was going to play, but I guess it was the best thing that happened to me. I played some matches, some very tough ones, and I won them,'' Huber said. ``If you haven't played for nine years, you don't even know how it is there. It's just different. You have to prepare for it mentally.''

Huber, ranked fourth in the world in 1996, is now 29th. She surprised eighth-seeded Nathalie Tauziat 6-3, 6-1 in the first round. In 13 tournaments this year, Huber hasn't advanced past the quarterfinals.

Both players were clearly frustrated throughout the two-hour battle. Huber was warned for racket abuse after tossing it into her chair, while Schett was warned for ball abuse after sending one flying into the crowd at one end of the stadium.

``I was getting very frustrated with myself because I just didn't take my chances like I normally do,'' Schett said. ``She has a lot of confidence because she qualified and beat another seeded player.''