Nadal is the highest-ranked player left in the draw

Spaniard Nadal reached the last 16 with a 6-4 6-4 win over compatriot Fernando Verdasco, while home favourite Roddick beat Olivier Rochus 6-3 7-6 (7-5).

But there was bad news for American fans when James Blake lost to Julien Benneteau of France 6-2 7-6 (7-1).

And Guillermo Canas - conqueror of Roger Federer on Sunday - was beaten 6-4 6-4 by Carlos Moya.

Federer's surprise defeat remained the talking point and Roddick admitted it had opened up the draw for everyone else.

For me it doesn't matter if Federer is in the tournament or not. I have beaten him before Rafael Nadal

"I want to beat Roger," said Roddick, who served 18 aces but made 33 unforced errors against Rochus.

"Obviously, it helps out everybody, it takes the toughest player out of the draw, but at the same time I'm going to have to figure it out one of these times anyway.

"You can't sit back and hope that he loses because that's not going to happen a lot."

Nadal, who plays Juan Carlos Ferrero next, was less concerned by the fate of Federer.

"For me it doesn't matter if he is in the tournament or not," said the world number two. "I have beaten him before.

"He is always in the other half of the draw so I have to concentrate on one match at a time."

Roddick will next face 15th seed Richard Gasquet of France, who defeated number 18 Jarkko Nieminen of Finland 6-3 1-6 6-3.

Last year's runner-up Blake committed 41 unforced errors against Benneteau, and when asked what went wrong he said: "Everything."

Fernando Gonzalez, the Australian Open runner-up, was a 7-6 (7-4) 7-6 (7-2) winner over Robin Soderling, and eighth seed Ivan Ljubicic beat Thomas Johansson 6-1 6-4.