Gisela Dulko knocks Maria Sharapova out of Wimbledon

Former champion Maria Sharapova of Russia saw her comeback attempt come to an early end, as Argentina's Gisela Dulko beat her, 6-2, 3-6, 6-4. Dulko faces 10th-seeded Nadia Petrova in the third round, after the Russian beat Shahar Peer of Israel, 6-3, 6-2.

Second-seeds Roger Federer of Switzerland and Serena Williams of the United States have advanced to the third round of the 2009 Wimbledon tennis championships in London.

Williams took advantage of her big serve and powerful ground strokes Wednesday as she dominated Australia's Jarmila Groth, 6-2, 6-1. Federer eliminated Spain's Guillermo García-Lopez, 6-2, 6-2, 6-4.

Federer is trying to pass American Pete Sampras as the sport's most successful major tournament winner by capturing his 15th Grand Slam title.

Eighth-seeded Victoria Azarenka of Belarus had an even easier time, dumping Ioana Raluca Olaru of Romania by the so-called "double-bagel" score of 6-0, 6-0.

In men's play, fourth-seeded Novak Djokovic of Serbia beat Germany's Simon Greul, 7-5, 6-1, 6-4. His next opponent will be number-28 American Mardy Fish, a four-set winner over another Serb, Janko Tipsarevic (6-4, 3-6, 6-1 ,6-4).