Rafael Nadal of Spain serves to Radek Stepanek of the Czech Republic during their tennis match at the Queen's Club Championships in west London June 9, 2011. [Photo/Agencies]

LONDON - Rafa Nadal suffered a late blip against unseeded Czech Radek Stepanek before reaching the quarter-finals of the Queen's Club championships on Thursday after Andy Murray and Andy Roddick both cruised through.

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The world number one, fresh from his record-equalling sixth French Open title, looked in total command against Stepanek as he served for the match in the second set but a rare collapse kept the Spaniard on court for longer than he wanted before he walked off with a 6-3 5-7 6-1 victory.

"For sure, I'm a bit tired," Nadal said on court before hurrying off to play doubles with partner Marc Lopez.

"5-2, 5-3, 40-15 he played well. I had a few mistakes and you know that's the turning point. The beginning of the third was tough but after that I think I played my best. Much better than yesterday."

Second seed Murray, who will spend the next few weeks shouldering Britain's hopes of a first men's grand slam champion since 1936, beat flashy Serb Janko Tipsarevic 6-4 7-6 despite losing his service at the start of each set.

Roddick, the third seed who is looking for a record fifth title at the traditional Wimbledon warm-up event, was equally impressive as he dispatched towering South African Kevin Anderson 6-4 6-4 to set up a quarter-final against Spain's Fernando Verdasco, a 7-5 6-1 winner against David Nalbandian.

Another Argentine to fall was Juan Martin del Potro who was bundled out in two tiebreaks by Frenchman Adrian Mannarino.

Croatia's Marin Cilic made it a bad day for south Americans as he ousted Brazil's Thomaz Bellucci 7-6 0-6 6-3 to seal a last-eight clash against Murray.

Nadal is usually ruthless when an opponent is on the ropes, but serving at 5-3 in the second set he wasted two match points and then threw in a double fault to give Stepanek a lifeline.

Then, at 5-5, he played another messy game and suddenly the mercurial Czech veteran was serving for the second set, which he did in some style, levelling the match with a lunging volley.

While the crowd, some of them perched on the balconies of the rambling Victorian clubhouse, loved it, Nadal was clearly not amused and stormed through the deciding set in quick time to set up a last eight meeting with fifth seed Jo-Wilfried Tsonga.

Murray, beaten by Nadal in last year's Wimbledon semi-final as the Spaniard marched towards a second title at the All England Club, made sloppy starts to each set against the bespectacled Tipsarevic.