Melbourne, Australia (SportsNetwork.com) - Novak Djokovic survived a tough first set, then rolled to a three-set win over Spain's Fernando Verdasco in the third round of the Australian Open.

Djokovic, the tournament's top seed, won 82 percent of his first serve points en route to beating Verdasco 7-6 (10-8), 6-3, 6-4.

The Serbian, who has won this title four times, moves on to face Gilles Muller.

Verdasco slammed 10 aces in the opening set, but did himself in with 28 unforced errors. Djokovic had 12 unforced errors of his own in the first set, but had just 12 more the remainder of the match.

Muller downed American John Isner 7-6, 7-6, 6-4. With Isner and Steve Johnson dropping their matches on Saturday, all the American men have been ousted.

Fourth seed and defending champion Stan Wawrinka moved on with a three-set victory over Finland's Jarkko Nieminen.

Wawrinka had 55 winners to just 18 for his opponent in the lopsided 6-4, 6-2, 6-4 Saturday encounter at Rod Laver Arena. The Swiss native avoided becoming the first defending Australian Open champion to lose in the third round since Petr Korda in 1999.

"It was a really good match from me today," Wawrinka said. "I was playing great, tried to be more aggressive than normal."

Up next for Wawrinka will be Spain's Guillermo Garcia-Lopez, who beat Canada's Vasek Pospisil, 6-2, 6-4, 6-4.

Milos Raonic, the No. 8 seed from Canada, moved on with a win over Germany's Benjamin Becker, 6-4, 6-3, 6-3. Raonic equaled his best performance at this event.

Feliciano Lopez, the No. 12 seed from Spain, will play Raonic in the round- of-16. Lopez beat Poland's Jerzy Janowicz, 7-6 (8-6), 6-4, 7-6 (7-3).