Second-seeded Amelie Mauresmo of France has been upset in her opener at the Sydney International tennis tournament in Australia, losing the second-round match 6-3, 7-5 to Ana Ivanovic of Serbia and Montenegro.

The world number-three Mauresmo struggled with her serve Tuesday, as she played in her first match since winning the season-ending WTA Championships in November. Ivanovic next faces sixth-seeded Svetlana Kuznetsova, who was leading Dinara Safina 6-3 when her fellow Russian withdrew because of foot blisters.

Mauresmo Eliminated from 2nd Round of Sydney International Tennis Tournament

In other results involving women's seeds, Belgians Kim Clijsters and Justine Henin-Hardenne cruised into the quarterfinals. The top-seeded Clijsters beat China's Li Na, 6-3, 6-1, while the number-five Henin-Hardenne cruised past Russia's Vera Dushevina, 6-2, 6-2.

Mauresmo Eliminated from 2nd Round of Sydney International Tennis Tournament

Third-seeded Patty Schynder of Switzerland was another upset victim, falling to Daniela Hantuchova, 3-6, 6-3, 6-4. The Slovakian next meets eighth-seeded Czech Nicole Vaidisova, who defeated Yuliana Fedak of Ukraine, 6-3, 6-3. In the late match, fourth-seeded Nadia Petrova advanced to the quarterfinals by downing fellow Russian Maria Kirilenko, 6-1, 6-2.

Mauresmo Eliminated from 2nd Round of Sydney International Tennis Tournament

In men's play, second-seeded Nikolay Davydenko moved into the second round with a 7-6, 6-3 win over Tomas Berdych of the Czech Republic, but three seeded players lost their matches.

Number-four Richard Gasquet of France, sixth-seeded Tommy Robredo of Spain and number-seven Czech Radek Stepanek all fell, while third-seeded Thomas Johansson of Sweden withdrew with a strained shoulder.

Igor Andreev of Russia beat Gasquet, 6-3, 6-4, while Russia's Dmitry Tursunov downed Robredo 7-6, 6-3 and Paradorn Srichaphan of Thailand ousted Stepanek, 6-3, 6-4.