After struggling in the first-round of the Australian Open tennis championships in Melbourne earlier this week, women's top-seed Serena Williams had an easier time in round two.

The American beat Belgium's Els Callens 6-4, 6-0 Thursday to advance to the third round.

Fourth-seed Kim Clijsters of Belgium scored the tournament's first shutout, beating Hungary's Petra Mandula in only 33 minutes, 6-0, 6-0.

Other women advancing to the third round include eighth-seed Anastasia Myskina of Russia, who beat Emmanuelle Gagliardi of Switzerland in three sets, 5-7, 6-2, 6-0, number-10 Chanda Rubin of the United States, who needed three sets to beat France's Mary Pierce 0-6, 6-4, 6-2, and 11th-seed Magdalena Maleeva of Bulgaria, who knocked out South Korean Cho Yoon-jeong in three sets, 2-6, 6-4, 6-1. Also winning were 14th-seed Anna Pistolesi of Israel, whose second-round opponent retired due to a leg injury, and 16th-seed Nathalie Dechy of France, who beat Czech Daja Bedanova in straight sets, 6-3, 6-3.

But sixth-seed Monica Seles of the United States fell to Czech Klara Koukalova in three sets, 6-7, 7-5, 6-3. Seles hurt her ankle in the first set and struggled to finish the match.

In men's second-round action, top-seed Lleyton Hewitt had little trouble with fellow Australian Todd Larkham, beating him in straight sets, 6-1, 6-0, 6-1.

Fifth-seed Carlos Moya of Spain became the highest-seeded men's player to fall, losing to American Mardy Fish in five sets, 3-6, 7-6, 6-4, 4-6, 6-2.

Third-seed Marat Safin of Russia advanced to the third round with a four-set win over France's Albert Montanes 6-3, 4-6, 6-4, 6-1. Number-six Roger Federer of Switzerland beat Germany's Lars Burgsmuller in straight sets, 6-3, 6-0, 6-3. Seventh-seed Jiri Novak of the Czech Republic needed five sets to beat Belgium's Olivier Rochus 7-6, 7-6, 4-6, 4-6, 6-3. Ninth-seed Andy Roddick of the United States overpowered Romania's Adrian Voinea in straight sets, 6-2, 6-2, 6-2.

Wimbledon runner-up and 10th-seed David Nalbandian of Argentina also won, beating Australia's Jaymon Crabb in straight sets, 6-1, 7-6, 6-3. But number-13 Fernando Gonzalez of Chile lost to Spain's Alberto Martin in four sets, 6-7, 6-3, 6-1, 7-6.