Hingis opened defense of her title with a 6-2, 7-6 (7-2) over Dominique Van Roost of Belgium to advance to the quarterfinals.

Two other seeded players secured berths into the second round. Sixth seed Nathalie Tauziat of France, at 32 the oldest player in the draw, downed Anne Kremer of Luxembourg, 6-4, 6-3.

Eighth seed Sandrine Testud of France rallied past American Chanda Rubin, 3-6, 7-5, 6-2 in a matchup of players who reached the quarterfinals of last week's Bank of the West Classic.

Another American recorded an upset as Amy Frazier eliminated seventh seed Anke Huber of Germany, 6-0, 7-6 (7-3).

Fifth seed Conchita Martinez of Spain, the 1995 champion and 1992 runner-up, faces Belgian teenager Kim Clijsters later today.

Anna Kournikova of Russia, a semifinalist at the Bank of the West, goes against American Alexandra Stevenson tonight in an all-teenage matchup of unseeded players.

A two-time champion here, Hingis is competing in her first event since her quarterfinal loss to eventual champion Venus Williams at the All-England Club. She made headlines last week when she announced she would not represent Switzerland at the upcoming Sydney Olympics, citing a heavy travel schedule.

The 19-year-old Hingis has won four titles this season and compiled a 46-6 record, including 23-3 on hard courts. She has reached four hardcourt finals in 2000, going 1-2 with one rained out.

Hingis won this event in 1997 over Monica Seles. She defeated Williams, 6-4, 6-0, in last year's final.

Van Roost, a former top-10 player, fell to 1-4 lifetime against Hingis, including a quarterfinal loss here last year.

California native Lindsay Davenport is seeded second, reigning Wimbledon champion Williams, is seeded third and Seles is fourth. Each received a bye into the second round.

In a first-round match Monday, American Jennifer Capriati was dismissed in straight sets by Russia's Elena Likhovtseva.

First prize is $87,000.