PARIS, May 30 (UPI) -- Three-time runner-up Roger Federer of Switzerland advanced but Novak Djokovic of Serbia lost in men's play Saturday at the French Open in Paris.
Federer, the second seed, rallied to beat Frenchman Paul-Henri Mathieu 4-6, 6-1, 6-4, 6-4.
The fourth-seeded Djokovic lost 6-4, 6-4, 6-4 to Germany's unheralded Philipp Kohlschreiber.
"What is disappointing was that I couldn't find the rhythm throughout the whole match," Djokovic said after his surprising loss. "I was trying not to be frustrated with a lot of unforced errors. Tried to be positive and just wait for the chances."
American Andy Roddick, the sixth seed, topped France's Marc Gicquel 6-1, 6-4, 6-4 after only 11 unforced errors; ninth-seeded Jo-Wilfried Tsonga of France trounced Belgium's Christophe Rochus 6-2, 6-2, 6-2; Argentina's Juan Martin Del Potro beat Russian Igor Andreev 6-4, 7-5, 6-4; and Frenchman Gabe Monfils was a 6-2, 4-6, 6-3, 6-1 winner against Austria's Jurgen Melzer.