Rafael Nadal and Roger Federer into Australian Open 2012 quarters

Nadal had a first-serve percentage of 80% and just 14 unforced errors

Rafael Nadal and Roger Federer swept past Feliciano Lopez and Bernard Tomic respectively to reach the Australian Open quarter-finals.

Nadal rarely needed to hit top form in beating his fellow Spaniard 6-4 6-4 6-2 on a sweltering Rod Laver Arena.

The second seed next plays seventh seed Tomas Berdych, who beat Nicolas Almagro in a stormy match.

Federer ended Australian Tomic's hopes with a dominant 6-4 6-2 6-2 win to set up a match with Juan Martin del Potro.

"I'm feeling fine," said Nadal, who had strapping on his right knee and left foot and has now reached the quarter-final stage without dropping a set for the fourth time in five years.

"It's positive to keep winning in straight sets, especially in these conditions. It was a very, very hot day.

"Feliciano is a very good friend of mine but I tried my best and so did he.

"I did what I had to do to win in straight sets and, against a really good player, that's very positive for me."

Nadal's all-round game was too much for 18th seed Lopez, whose passive approach played into his compatriot's hands.

Del Potro is into the last eight of a major for the first time since 2009

Possessing a big serve, good touch at the net and powerful forehand, Lopez was expected to move forward as often as possible.

But, bizarrely, he opted to take on Nadal at his own game, becoming engaged in baseline rallies he was unlikely to win.

Nadal dropped just four points on serve in the opening set and a solitary break in the third game made the difference.

The second was more competitive as Lopez finally began to volley, but he could not keep it up and Nadal broke for 4-3 before serving out.

Two further breaks in the third set helped confirm the 10-time Grand Slam champion's progress.

Bidding for his 17th Grand Slam title, Federer was ruthless in his victory over crowd favourite Tomic, 19.

The 30-year-old, who has not lost to a teenager since 2006, broke the Australian six times to advance to his 31st consecutive quarter-final where he will face Del Potro of Argentina.

"I thought I played a really good match," said four-time Australian Open champion Federer. "I knew I had to. Anything else wouldn't have done the job."

Del Potro overcame Philipp Kohlschreiber to reach the quarter-finals of a Grand Slam for the first time since winning the 2009 US Open.

With his wrist problems finally in the past, the 11th seed from Argentina saw off German Kohlschreiber 6-4 6-2 6-1.