Hingis, the top seed, has won three titles this season, but none since capturing consecutive Middle Eastern events in February.

The 20-year-old from Switzerland began her claycourt season with a quarterfinal showing at the Bausch & Lomb Championships. In April, she reached the final at the Family Circle Cup before losing to American Jennifer Capriati, who beat Hingis in the Australian Open final in January.

Last week, Hingis fell in the semifinals at the German Open in Berlin to eventual winner Amelie Mauresmo of France.

Hingis, the 1998 champion and 1996 runner-up, goes against Russia's Tatiana Panova in a second-round match Tuesday. Panova rallied past American qualifier Jill Craybas, 3-6, 7-5, 6-3, to set up Tuesday's meeting with the world No. 1.

No. 16 Magui Serna was the lone seeded player in action Monday, but made a quick exit as Henrieta Nagyova of Slovakia eliminated the Spaniard, 2-6, 6-3, 6-2.

In an unseeded match of note, Rita Kuti Kis of Hungary defeated former French Open champion Iva Majoli of Croatia, 6-4, 6-4. Kuti Kis will face Capriati in the second round.

Capriati, the second seed, is coming off a runner-up effort in Berlin. She owns a 27-5 match record and has won two of five finals this season, including her first career Grand Slam title at the Australian Open.

Spain's Conchita Martinez is back hoping to win this event for a fifth time. The third-seeded Martinez, who won four straight titles here from 1993-1996, is just 5-4 this season on clay -- her best surface. Last year, she went 22-6 on the dirt, advancing to the final of the French Open.

Seeded fourth here, Mauresmo won her tour-leading fourth title on Sunday in Berlin to raise her world ranking from No. 9 to No. 6. She claimed consecutive titles in her native France in February, in addition to the Bausch & Lomb Championships on clay in April.

Nathalie Tauziat of France is seeded fifth, followed by Kim Clijsters of Belgium, Arantxa Sanchez-Vicario of Spain and Bulgaria's Magdalena Maleeva. The top eight seeds received first-round byes.

Germany's Anke Huber is seeded ninth, followed by reigning French Open champion Mary Pierce of France.

Pierce, who has been hampered by injuries this season, competes in just her second event since February when she goes against Russia's Nadia Petrova on Tuesday.

Justine Henin of Belgium, who sprained her ankle in the German Open semifinals, is seeded 11th. Sandrine Testud of France, American Meghann Shaughnessy, Yugoslavian teenager Jelena Dokic, Barbara Schett of Austria, Serna and Paola Suarez round out the top 17 seeds.

First prize is $176,000.