KEY BISCAYNE, Fla. -- The Lipton Championships lost a nine-time Grand Slam winner Monday when Anna Kournikova beat Monica Seles in a third-round match, 7-5, 6-4. The 16-year-old Russian rallied from deficits of 4-1 in the first set and 3-1 in the second.

The loss put an end to Seles' first 1998 comeback bid. The world's former No. 1 player, who lives in Florida, had taken time out from the game to be with her ailing father, Karolj, who has cancer. She won here in 1990 and 1991 and lost to Hingis in last year's final.

Another 16-year-old, Serena Williams, advanced to a quarterfinal matchup against top-ranked Martina Hingis. Williams beat Patty Schnyder 6-0, 4-6, 6-3 and Hingis outlasted Sandrine Testud 6-3, 5-7, 6-2.

WILLIAMS' MORE CELEBRATED SISTER, Venus, also advanced. Sixth-seeded Amanda Coetzer lost to Silvia Farina 6-7 (3-7), 6-2, 6-1.

If Venus and Serena win their quarterfinal matches, the two Williams sisters will battle for a berth in the final. Venus defeated Serena in the second round of the Australian Open.

Hingis, who dropped just one game in her first two matches, improved to 18-2 this season and has won 42 of 43 matches outdoors in the United States over the last two years. Her only loss came to Lindsay Davenport in the semifinals in Los Angeles last year.

In other women's fourth-round play, third seed Jana Novotna of the Czech Republic, a two-time semifinalist, crushed 14th-seeded Anke Huber of Germany, 6-2, 6-2. Novotna, who improved to 8-3 lifetime against Huber, will battle eighth seed and two-time champion Arantxa Sanchez Vicario of Spain in the round of eight. Sanchez Vicario, seeking her second title of the year, bounced Maria Alejandra Vento of Venezuela, 6-2, 6-1.

Davenport, the second seed, improved to 12-4 on hardcourts this year by dispatching No. 12 Nathalie Tauziat of France, 6-2, 6-1, Monday night.