New York, August 30:

Svetlana Kuznetsova’s reign as US Open champion ended unceremoniously on Monday, the first time in the Open era that the women’s defending champion was knocked out in the first round.

Fellow Russian Ekaterina Bychkova, ranked 97th, shocked the fifth-seeded Kuznetsova 6-3, 6-2. Compatriot Maria Sharapova, the top seed, advanced with a 6-1, 6-1 victory over Greece’s Eleni Daniilidou.

Sharapova led a string of women’s seeds into the second round, including Serena and Venus Williams, Belgian Kim Clijsters, and Russian Nadia Petrova.

Clijsters, the fourth seed, dispatched German Martina Muller 6-1, 6-2. Serena Williams, eighth seed, had a 6-1, 6-3 victory over Taiwanese Chan Yung-Ja. Venus Williams, the 10th seed, defeated Rika Fujiwara of Japan 6-3, 6-1.

On the men’s side, 35-year-old two-time champion Andre Agassi and 19-year-old second seed Rafael Nadal advanced with straight-set wins. Agassi cruised past Romanian Razvan Sabau 6-3, 6-3, 6-1.

Fourth seed Guillermo Coria cruised to a straight-sets win over Felix Mantilla and 10th-seeded Mariano Puerta of Argentina defeated Israeli Noam Okun in four sets. American wild card Brian Baker posted the biggest early upset on the men’s side, ousting ninth-seeded Argentinian Gaston Gaudio 7-6, 6-2, 6-4.

Results: Men’s — Xavier Malisse beat Jan Hernych 6-2, 7-5, 6-2; Nicolas Massu beat Jan-Michael Gambill 7-6, 6-2, 6-3; Brian Baker beat Gaston Gaudio 7-6, 6-2, 6-4; Rafael Nadal beat Bobby Reynolds 6-3, 6-3, 6-4; Jiri Novak beat Dick Norman 6-4, 6-4, 6-2; Tommy Haas beat Peter Luczak 3-6, 6-3, 6-2, 6-3; Guillermo Coria beat Felix Mantilla 7-6, 6-1, 6-3; Andre Agassi beat Razvan Sabau 6-3, 6-3, 6-1. Women’s — Serena Willi-ams beat Chan Yung-Jan

6-1, 6-3; Daniela Hantuchova beat Camille Pin 6-3, 6-1; Kim Clijsters beat Martina Muller 6-1, 6-2; Venus Williams beat Rika Fujiwara 6-3, 6-1; Sania Mirza beat Mashona Washington 7-6, 6-7, 6-4; Shenay Perry beat Alica Molik 6-4, 6-4; Maria Sharapova beat Eleni Daniilidou 6-1, 6-1.