Andy Murray is through to the next round of the Australian Open
Andy Murray is through to the next round of the Australian Open REUTERS

Andy Murray cruised into the Australian Open quarter-finals for a third consecutive year after his opponent, Mikhail Kukushkin, was forced to retire through injury while 6-1 6-1 1-0 down.

The British No.1 was rarely troubled as he found his rhythm early to lead comprehensively by the time Kukushkin pulled out with a left hip flexor problem.

A mere 49 minutes against a clearly troubled opponent provided us with few glimpses of Murray's current mindset but the ease with which the World No.4 crushed his opponent augers well for the second week in Melbourne.

And Murray will need every reserve of strength for Wednesday's match after Kei Nishikori beat Jo-Wilfried Tsonga to set up a quarter-final clash with the Scot.

"I saw a little bit of the match. Kei is playing really, really well. I practised with him a few times. He's very good, very deceptive. For somebody that's not the tallest guy he creates a lot of power from the back of the court. He deals with pace well. He can slice. He moves well," Murray is quoted in the Guardian.

"He was hitting a lot of winners out there. He was dictating all the points from the back of the court which is difficult against someone like Tsonga. He's won a few long matches here as well. I saw him in the gym a lot. I think he's gotten in better shape as well."

But Murray will not feel too daunted against the 24th-seed - against whom he has a winning record - particularly in light of a "boring" encounter with Kukushkin.

"I played him [Kukushkin] a few weeks ago at Brisbane and it was three tough sets and I expected another tough one today," Murray told the BBC.

"I hadn't seen him play before Brisbane and he hit some huge shots early and made me work.

"It is tough for him for that to happen in the fourth round of a Grand Slam for the first time."