“He was playing great early on,” Roddick conceded. “The biggest thing was just to turn it around in the second set.”
Djokovic, the 2008 Australian Open champion, was leading Viktor Troicki 6-2 when his Serbian Davis Cup teammate retired because of a strained stomach muscle. Djokovic will next play No. 14 Nicolas Almagro, who beat No. 17 Ivan Ljubicic 6-4, 7-6 (8), 6-3.
“It’s not really the way you want to win,” Djokovic said.
No. 9 Fernando Verdasco advanced with a 6-2, 6-4, 6-3 win over Kei Nishikori of Japan, setting up a match against Berdych in the fourth round. Berdych beat Richard Gasquet of France 6-2, 7-6 (3), 6-2.
Stanislas Wawrinka of Switzerland defeated No. 12 Gael Monfils 7-6 (4), 6-2, 6-3, breaking the Frenchman in the last game. Warwinka will play Roddick in the fourth round.