Rafael Nadal and Andy Roddick reach Queen's last eight

World number one Rafael Nadal recovered from a second-set blip to edge past Radek Stepanek into the quarter-finals in the Aegon Championships at Queen's.

Nadal lost five games in a row in the second set as fatigue appeared to set in after his recent French Open win.

But he bounced back impressively to beat his Czech opponent 6-3 5-7 6-1.

Four-time Queen's winner Andy Roddick also made the last eight after brushing aside 6ft 8in South African Kevin Anderson 6-4 6-4 in overcast London.

The American third seed was tested well by his 16th-seed opponent but raised his game impressively at the end of each set as he eyes a record fifth title.

The 28-year-old, who has lost in the Wimbledon men's singles final three times, will now play Fernando Verdasco in the quarter-finals.

Verdasco, the Spanish seventh seed, beat Argentina's number nine seed David Nalbandian 7-5 6-1 on Thursday.

"I love being here, I love this tournament, I love this whole month over here [in England]," Roddick told BBC Sport. "So I'm trying to make the most of it. I was solid.

"I had a game plan, and I stuck to it. There weren't going to be many breaks with the way we both serve. That's grass-court tennis."

Nadal, meanwhile, was grateful to come through a stern test against Stepanek, saying: "At the beginning of the third [set], it was tough, but I feel I played my best in the third set. I think I played much better than Wednesday.

"For sure, I'm a bit tired, but I always play with this fantastic crowd and fantastic atmopshere and it's always a pleasure to be here.

"I have motivation to play. For sure Wimbledon is there [in the future] but right now I focus on Queen's."

Nadal's last eight opponent will be Frenchman Jo-Wilfried Tsonga after his opponent, compatriot Michael Llodra, was forced to retire with a thigh injury at 4-3 down in the first set.

Another Frenchman, sixth seed Gilles Simon, was also forced to quit his match - this time due to back pain - when trailling Adrian Mannarino 6-7 (4-7) 6-4 3-0 in a second-round match that had resumed after being suspended on Wednesday at one set all.

And Mannarino went on to complete a shock victory over former US Open champion Juan Martin del Potro of Argentina 7-6 (7-3) 7-6 (9-7) to book his place in the quarters.