Roger Federer played the sort of tennis to suggest he could yet win an 18th grand slam title as he annihilated Tomas Berdych at the Australian Open.

After six months out through injury, Federer had looked rusty in his opening two rounds here but the Swiss produced an awesome display to beat world number 10 Berdych 6-2 6-4 6-4.

He will now face Kei Nishikori for a place in the quarter-finals, where the winner could meet Britain's Andy Murray.

A kind draw meant Federer was paired with qualifiers in both his first two matches in Melbourne but Berdych, a four-time grand slam semi-finalist and Wimbledon runner-up in 2010, represented his first real test.

The 35-year-old passed it with flying colours, hitting 40 winners and conceding not a single break point during an hour and a half of scintillating tennis.

"I did surprise myself," Federer said on court afterwards. "I'm happy to do as well as I did, even though I struggled in the early rounds today was different.

"I served great, the court was fast, it's been unbelievable."

Federer looked back to somewhere near his best of recent years (Getty)

Federer was playing only his third official match after taking off the second half of 2016 to overcome niggling injuries to his knee and back.

Now ranked 17th in the world, his performance on Rod Laver Arena will certainly encourage those eager to see the veteran add one more title to his record 17 major triumphs.

Nishikori, however, who knocked Andy Murray out of the US Open in September, will be a step up again, particularly if Federer is still lacking full fitness.

Nishikori knocked Murray out of the US Open (Getty)

The Japanese is renowned as one of the sharpest, quickest and most enduring athletes in the game.

"I guess I'm ready now," Federer said. "There's no turning back.

"I like Kei, I'm a fan of his game. He's a nice kid and has had a great few seasons now. I remember playing him in Japan when he was 17 - he's just a good guy, I'm happy to play against him.

"His backhand is maybe the best in the business right now so I've got my work cut out but hopefully I can play a good match."

Wawrinka dropped the first set before beating Troicki (Getty)

Nishikori should be feeling fresh after giving away only 12 games himself in a 6-4 6-4 6-4 win over Slovakian Lukas Lacko.

"For sure it's not going to be easy against Roger," Nishikori said.