Hingis will meet fifth-seeded Mary Pierce of France for the third straight year in the quarterfinals. Pierce defeated Hingis in 1997 en route to the final but Hingis prevailed last year.

Williams, coming off a three-set win over Conchita Martinez of Spain on Wednesday night, faces Barbara Schett of Austria.

Hingis beat Sandrine Testud of France, 7-6 (7-5), 7-6 (7-5) Tuesday night in her first-round match. Pierce rallied to beat Anna Kournikova of Russia, 6-7 (3-7), 7-6 (7-5), 6-0 on Monday.

Overall, Hingis has won a WTA Tour-leading seven titles in 1999, but has come up short in the last two finals she has appeared in. She lost to Williams in her homeland tournament in Zurich last month and fell to Lindsay Davenport in Sunday's final of the Advanta Championships in Philadelphia. Hingis defeated the-then top-ranked Davenport in four sets in last year's season finale.

Williams cruised through the first set before pulling out a 6-2, 5-7, 6-4 victory over Martinez.

The 19-year-old Williams qualified for the exclusive 16-player field last year but was forced to withdraw due to a knee injury. She has reached 10 finals this season, taking the crown in Oklahoma City, Key Biscayne, Hamburg, Rome, New Haven and Zurich. However, she was somewhat overshadowed by her younger sister Serena, who won the family's first Grand Slam singles title at the U.S. Open.

Schett knocked off Arantxa Sanchez Vicario of Spain, 6-1, 6-4 in the first round on Monday.

Currently ranked a career-high No. 7 in the world, Schett has had a breakout year, going 47-24. She has reached only one final, losing to Nathalie Tauziat at the Ladies Kremlin Cup in Moscow three weeks ago.

Davenport, the second seed, will play Anke Huber of Germany and No. 6 Nathalie Tauziat faces Dominique Van Roost of Belgium in the other quarterfinal matches on Friday.

This event, which gathers the top 16 players in the world, offers a first prize is $500,000 from a total purse of $2 million.