Roger Federer barely broke a sweat as he strolled into the Australian Open final four with a straight-sets win over German giant-killer Mischa Zverev on Rod Laver Arena.

The Swiss maestro breezed to a 6-1 7-5 6-2 victory, needing only 19 minutes to wrap up the first set in outclassing Zverev, who last round eliminated world No.1 Andy Murray.

In the semi-finals Federer will face fellow Swiss Stan Wawrinka, who earlier ousted Frenchman Jo-Wilfried Tsonga also in straight sets.

Federer admitted after the match that he had already surpassed his expectations for the tournament, which is his first grand slam after six months out following knee surgery.

“It was not to play semis … I thought I was maybe going to win a few rounds – depending on the draw maybe get to a fourth round or the quarters,” Federer said.

“I never thought it was going to be this good, and here I am in a semi against Stan. It couldn’t be cooler for the both of us.”

Gunning for his first grand slam title in five years, Federer delivered a precision performance, particularly in the first set against the world No.50 Zverev.

The two players last met in Halle in 2013 when Federer blitzed his opponent 6-0 6-0 and it looked like Federer’s run of games would be extended past 18 until Zverev broke through at 5-0.

The second set produced a closer contest with Zverev breaking the 17th seed early to go to a 3-1 lead.

But it was his only break of the match as Federer hit back and lifted his play towards the end of the set, crushing Zverev’s spirit to break him to love at 5-5 before serving out the set.

The 35-year-old continued the third set in the same style to book his 41st appearance in a grand slam semi-final and his 13th at the Australian Open in the past 14 years.

It matched Federer’s 2016 result, with the last of his four crowns at Melbourne Park coming back in 2010.

Federer’s performance was all the more impressive given he was coming off a five-set win over Japan’s Kei Nishikori.

-AAP