Hingis has won all WTA Tour Tier I tournaments and three of the four Grand Slams but has not captured this event, which has been won by all the other No. 1 players in the last 20 years.

The top seed from Switzerland will meet Virginia Ruano-Pascual of Spain in a second-round match on Tuesday. Ruano-Pascual beat Sweden's Sofia Arvidsson, 6-3, 6-2 in a first-round match on Monday.

Hingis lost in the semifinals at the Ericsson Open in Miami two weeks ago to Venus Williams but has three titles this season and a 33-4 match record. She and the other top 16 seeds received byes out of the first round.

Second seed and 1995 champion Conchita Martinez of Spain brings a three-match losing streak into this event. Martinez's best stretch this season was at the beginning of the year in Australia, when she reached the quarterfinals at Gold Coast and the semifinals at Sydney. She has lost four of her last five matches.

Martinez will face the winner of the match between Nicole Pratt of Australia and Silvia Farina of Italy in the second round.

Martinez lost in last year's final to Monica Seles, who withdrew due to a continuing foot injury.

Elena Dementieva, the third-seeded Russian, has won 10 of her last 13 matches. She reached her first WTA Tour final at the Mexican Open last month and followed with a quarterfinal effort at Indian Wells and a semifinal showing at Miami.

Dementieva will meet Nathalie Dechy of France in the second round. Dechy downed Shinobu Asagoe of Japan, 1-6, 7-5, 6-1 on Monday.

Fourth seed Amanda Coetzer of South Africa advanced to the fourth round at the Ericsson Open and defeated Dementieva in Acapulco to win her first title of the year.

Coetzer will face the winner of the first-round match between Tatiana Panova of Russia and Rachel McQuillan of Australia in the second round.

No. 5 Mary Pierce of France will participate in the her first match since falling in the quarterfinals at the Dubai Open in February. The 1998 champion here, she withdrew from her last few tournaments with tendinitis on both ankles.

Pierce will face the winner of the first-round match between Americans Meilen Tu and Marissa Irvin.

Sixth seed Amelie Mauresmo of France has won 10 consecutive matches, sweeping the titles in Paris and Nice in February.

She will face the winner of the first-round match between Kristina Brandi of the United States and Asa Carlson of Sweden.

Two-time champion Arantxa Sanchez-Vicario of Spain, fresh off winning her first title of the year at Porto, Portugal last week, is the seventh seed. Sanchez-Vicario captured her first championship since Cairo in 1999, although she was a finalist on claycourt tournaments at Hilton Head and Hamburg, Germany last year.

Sanchez-Vicario will play Pavlina Nola of Bulgaria, who beat Ruxandra Dragomir Ilie of Romania, 6-4, 6-2 on Monday.

American Chanda Rubin is seeded eighth, followed by Paola Suarez of Argentina, Americans Meghann Shaughnessy, Amy Frazier and Lisa Raymond, Yugoslavian Jelena Dokic, Gala Leon Garcia of Spain, Henrieta Nagyova of Slovakia, and Elena Likhovtseva.

In the only night match, Anastasi Myskina of Russian knocked off Iva Majoli of Croatia, 6-3, 6-1.

In other action on Monday, Switzerland's Patty Schnyder beat Canadian Jana Nejedly, 7-5, 6-3; Sandra Cacic of the United States defeated Joannette Kruger of South Africa, 6-3, 5-7, 6-3; American Jennifer Hopkins downed Germany's Andrea Glass, 6-1, 3-6, 6-3; Jill Craybas of the United States beat countrywoman Bettanie Mattek, 4-6, 6-1, 6-3 and Maria Emelia Salerni of Argentina defeated Marline Weingartner of Germany, 6-4, 6-2.