World number one Roger Federer avenged his defeat to Tommy Haas earlier this month by overcoming the German in a five-set thriller in the fourth round of the Australian Open on Monday. The Swiss ace took charge of the match winning the two first sets before being canceled out by Haas, forcing a decisive set. Federer, bidding for his seventh Grand Slam, finally prevailed in the decider to seal a 6-4, 6-0, 3-6, 4-6, 6-2 victory over the German and advance to the quarterfinals where he faces fifth-seeded Nikolay Davydenko. Davydenko also endured a tough five-setter to book his last-eight berth as he edged past Slovak Dominik Hrbaty 4-6, 4-6, 6-4, 6-2, 6-3.
Hingis Elsewhere, France's Sebastien Grosjean eased past compatriot Paul-Henri Mathieu to set up a quarterfinal clash with Germany's Nicolas Kiefer who beat Argentine Juan Ignacio Chela. In women's action, second-seed Kim Clijsters secured passage to the last-eight as she topped Italy's Francesca Schiavone 7-6 (7-5), 6-4 despite dropping three service games. The 22-year-old Belgian next takes on returning star Martina Hingis who ousted home favorite Samantha Stosur 6-1, 7-6 (10-8). The last two spots in the quarterfinals were claimed by third-seeded Amelie Mauresmo and seventh-seeded Patty Schnyder who beat Czech teenager, Nicole Vaidisova and former French Open champion, Anastasia Myskina respectively.