Second-seeded Andy Roddick advanced to the semifinals after defeating Marin Cilic 6-4, 7-6 (5).

Nadal, looking sluggish throughout the match, was broken in the last game of the first set and then failed to win a single point in the tiebreaker.

"It was tough," the Spaniard said. "I didn't really play very well. But anyway, I am happy with my tournament."

Nadal got to the same stage here last year and went on to reach the Wimbledon final, where he lost to Roger Federer. Nadal plans to go home to Mallorca, Spain, for a few days to relax before returning for Wimbledon, which starts June 25.

"I need to disconnect, play some golf, watch a little bit (of soccer), have some fun with the friends," he said. "I need put the racket very far from me for two days."

Mahut, who entered with a 6-11 record this year, looked surprised when his final shot bounced off the edge of the net beyond Nadal's racket.

He will face Arnaud Clement, who defeated Ivo Karlovic 7-5, 6-4 in another quarterfinal.

Roddick held off a break point at 5-4 with a service winner to take the first set, but had to rally from 4-1 down in the second as he failed to find any consistency.

"I played spotty today," Roddick said. "I was a little bit sloppy with some of the errors. If I want to get through two more matches and try to win this tournament again, I'll have to do better than that."

The American, who is aiming for his fourth title at Queen's, will face Dmitry Tursunov, who rallied from 2-4 in the final set to upset third-seeded Fernando Gonzalez 6-3, 6-7 (5), 6-4.

Gonzalez led 2-0 in the third set when the match was interrupted by rain for a second time. Tursunov evened it at 4-4, prompting Gonzalez to smash his racket.