CHARLESTON, S.C. (AP) -- Martina Hingis has not played her best tennis recently. And she's not the only one who has noticed.

Hingis began 2001 in fabulous fashion, beating the Williams sisters at the Australian Open, winning tournaments in Sydney, Qatar and Dubai and looking like the world's best player. But she lost to Kim Clijsters at Indian Wells, fell to Venus Williams in the semis at the Ericsson Open and was defeated by Arantxa Sanchez-Vicario a week ago at Amelia Island.

``I don't think at the moment Martina is playing the great tennis that she had been playing,'' said Iva Majoli, who was up a set and 2-0 on the top-seeded Hingis at the Family Circle on Thursday. ``Also her confidence is maybe not at the top level.''

Maybe that's changing.

Hingis, a Family Circle champion in 1997 and 1999, won the next six games of the second set and closed out Majoli to win her 12th straight tournament match.

``Maybe the last three tournaments I wasn't playing as well and it was just a lot of mental'' errors, Hingis said. ``Maybe I had some disappointing losses, but if you go through those tough matches, you build on confidence like today.''

Hingis will need all the confidence she can get. Next up is No. 7 Amelie Mauresmo, one of the hottest players on tour with victories in her past three tournaments -- Paris, Nice and Amelia Island.

Mauresmo defeated Lisa Raymond 7-5, 7-5 on Thursday.

``I think I had a good test today and coming into (Friday's) match it's going to be very interesting,'' said Mauresmo, who lost to Hingis on clay at the 1999 French Open. ``Playing Martina, I'm ready for that.''

Others advancing to the round of eight were No. 2 Jennifer Capriati, No. 3 Conchita Martinez, No. 4 Amanda Coetzer and unseeded Marlene Weingartner.

Defending champion Mary Pierce, the sixth seed, fell to No. 10 Amy Frazier 7-5, 6-7 6-4.

Pierce had trouble with her back -- she withdrew from the Amelia Island tournament last week -- from the start of this one.

``I'm not one to make excuses. If I didn't think I could play, I wouldn't be out there,'' Pierce said. ``I think it's more about Amy playing well.''

Frazier won eight of nine games to win the first set and led 5-1 in the second.

But Pierce, who asked for a trainer midway through the second set, fought off two championship points at 5-3, won the second-set tiebreaker and led 3-1 in the final set.

Frazier then started hitting harder, deeper shots to regain control. She's won five of the final six games to advance.

``She wasn't moving the way she can, but at the same time, she's such a dangerous player that I had to concentrate on my game,'' Frazier said.

Hingis looked like she would bow out early at the Family Circle for the first time since 1996.

Majoli may be best known for beating Hingis to win the 1997 French Open title -- the only Grand Slam championship Hingis did not win that year. This time, Majoli broke Hingis' serve three times during her early run.

``The first couple, three games, I was up on my serve and always I felt like those games belonged to me and then they were going her way,'' Hingis said.

But Majoli said she was suffering from an illness that left her weak and congested the final two sets.

``I couldn't feel my legs,'' said Majoli, who received treatment during the match. ``My nose, my throat, everything was blocked.''

Mauresmo needed three sets to defeat Raymond at Amelia Island's third round a week ago, but said she came here with additional confidence from winning that tournament.

``I played a little better than last week, so that probably made the difference,'' Mauresmo said.

Capriati reached this event's final about a month after turning pro in 1990. But her 6-4, 6-2 win over No. 15 Henrieta Nagyova was only the second time in six visits since that Capriati, the Australian Open winner, has advanced past the third round.