The top-seeded Nadal, coming off his triumph at the French Open, was taken to the limit before downing Kei Nishikori in the third round 6-4, 3-6, 6-3. His quarterfinal opponent will be Ivo Karlovic, who defeated Fernando Gonzalez 6-3, 7-5.

Roddick, seeded third, advanced when Mardy Fish retired after the first set. Roddick captured the opening set in a tiebreak 7-5.

Roddick will next meet Andy Murray, who rallied to oust Ernests Gulbis 5-7, 6-1, 6-4.

The other quarterfinals will find Richard Gasquet taking on David Nalbandian and Lleyton Hewitt meeting Novak Djokovic.

Djokovic, the second seed, had to come from behind before defeating Janko Tipsarevic 2-6, 6-4, 6-4.