MELBOURNE, Australia -- His right knee and left ankle taped, Rafael Nadal didn't look to be in any pain as he gave friend Feliciano Lopez the runaround Sunday, winning 6-4, 6-4, 6-2 to reach the Australian Open quarterfinals .
Nadal, who bizarrely hurt his knee while sitting in a chair the day before the tournament began, is one win away from a possible semifinal against old rival Roger Federer after beating his fellow Spaniard for the ninth time in 11 matches.
Federer ended the run of Australian teenager Bernard Tomic 6-4, 6-2, 6-2.
"Feliciano is one of my best friends on tour. That's the game. That's the sport," said Nadal, who hasn't dropped a set in four matches. "You understand that's only a game. You understand that everybody wants to win; everybody wants to finish the match with the best result."
On a sunny day with the temperature rising to 91, both players sat with ice towels around their necks during the changeovers.
Nadal needed treatment from the trainer for a left ankle problem after three games of the first set. By that time, he had already broken serve and he did the same early in the next two sets to maintain control against Lopez.
"I am fine," Nadal said. "It was a very, very hot day. I think it's positive to keep winning in straight sets."
Nadal plays Tomas Berdych next, hoping to avoid a third straight quarterfinal loss in Melbourne. Defending the title in 2010, the Spaniard retired with a knee injury against Andy Murray. A year ago, he was hampered by a hamstring problem in a straight-sets loss to David Ferrer.
"Hopefully not happen this time," Nadal said. "I had a bad experience last two years here. It's tough have to go out of a tournament like Australia in quarterfinals."
Berdych beat Nicolas Almagro of Spain 4-6, 7-6 (5), 7-6 (3), 7-6 (2).
Federer hasn't lost to a teenager since 2006 and that run continued Sunday as he disappointed the home crowd with a comprehensive win over the 19-year-old Tomic.
Tomic had beaten seeded players Fernando Verdasco and Alexandr Dolgopolov in earlier rounds, but Federer was a step-up in class. The 16-time Grand Slam champion broke six times as he set up a quarterfinal against 11th-seeded Argentine Juan Martin del Potro.
"I thought I played a really good match," said Federer, through to his 31st straight Grand Slam quarterfinal. "I knew I had to. Anything else wouldn't have done the job tonight."
Information from The Associated Report was used in this report.