KEY BISCAYNE, Fla. (AP) - Carlos Moya, scrambling to protect his new No. 1 ranking, rallied past Jason Stoltenberg 6-7 (5-7), 6-1, 7-5 Sunday in the third round at the Lipton Championships.

Top-ranked Martina Hingis had an easier time, beating Amy Frazier 6-1, 6-1. Steffi Graf and Monica Seles also won.

In other men's play, fifth-seeded Patrick Rafter lost his grudge match against Nicolas Kiefer, 7-6 (7-5),6-4. Rafter, complaining that Kiefer was too cocky, had promised a ``fiery'' performance against the German.

No. 6 Tim Henman lost to Jerome Golmard 6-4, 7-6 (9-7).

Unseeded Vince Spadea, one of only two Americans left in the men's draw, reached the fourth round by beating Fabrice Santoro 6-3, 6-2. No. 4 Alex Corretja, No. 12 Greg Rusedski and No. 14 Thomas Enqvist also advanced.

Second-seeded Pete Sampras was scheduled to play Sunday night against Jonas Bjorkman.

Moya was down a service break in the second set against Stoltenberg, then won the next seven games.

The Spaniard benefited in the next-to-last game of the match from two overrules by the chair umpire, including one that cost Stoltenberg the game. Instead, Moya took a 6-5 lead, then served out the match.

``I've been a little bit lucky, but I have to be very happy with that match,'' Moya said following his second victory in 24 hours. ``I like to get some rhythm. Even though I'm not playing my best, I won both matches. That means I've got a lot of confidence.''

Graf, seeded seventh, beat Henrieta Nagyova 6-1, 6-3, and No. 3 Seles swept Conchita Martinez 6-2, 6-1. Australian Open finalist Amelie Mauresmo, seeded 14th, lost to Elena Likhovtseva 4-6, 7-6 (7-5), 6-1.

Graf, a five-time Lipton champion, was pleased with her victory over Nagyova.

``It's been going extremely well,'' she said. ``I've been really going for my shots, serving extremely well, returning well. It seems whatever I'm trying out there, it really is going the right direction.''

Graf, seeking her first tournament title this year, advanced to a fourth-round matchup against 1998 Wimbledon finalist Natasha Zvereva. Graf leads the series 19-1, with Zvereva's only victory at Wimbledon last year.