A perfect fourth-round result at the Australian Open has brought Britain’s Andy Murray a step closer to the grand slam title he so desperately seeks.

But the fourth seed realises the hardest work is still to come.

Murray needed do little more than turn up for his match against Kazakhstan’s Mikhail Kukushkin on Rod Laver Arena on Monday to win and advance to his fifth grand slam quarter-final.

Kukushkin at least registered a service break before retiring from the match with the score at 6-1 6-1 1-0 in Murray’s favour.

On a day of blazing sun and soaring temperatures, the result was greeted with relief by Murray.

“It’s perfect,” Murray said.

“You just need to make sure that today and tomorrow, you hit enough balls and make sure you don’t lose any rhythm.”

Murray, who is playing in his 25th grand slam, is the odd man out in the world’s top four, being the only member of the quartet not to have won a grand slam.

He’s made the quarters 10 times and has been a finalist on three occasions, including the past two years in Melbourne.

In a bid to squeeze something more out of his game, he has employed former tennis great Ivan Lendl as his coach.

But he said he didn’t expect the benefits to become apparent until later in the year.

“You’re kind of absorbing a lot of different information – you’re asking a lot of questions,” Murray said.

“Ivan’s giving a lot of good answers – interesting ones.

“If I had no coach here, I’d be OK.

“But you just get that little bit of extra help from someone that’s been there and done it many, many times.”

Murray plays 24th seed Kei Nishikori in the quarters following the Japanese player’s defeat of sixth seed Jo-Wilfried Tsonga of France.

The 2-6 6-2 6-1 3-6 6-3 win made Nishikori the first Japanese player in 80 years to reach the Australian men’s quarters and only the second in the Open era to reach the final eight of a grand slam.

The last Japanese men to reach the quarters in Australia were Ryosuki Nunoi and Jiro Satoh in 1932.

Only one other Japanese man, Shuzo Matsuoka at Wimbledon in 1995, has made the quarters of a grand slam in the Open era.

The 22-year-old Nishikori has claimed only one title in his four years on the ATP Tour.

After being troubled by injury in 2009 when his world ranking blew out to 420th, he improved over the past two seasons to finish 2011 at 25th.

His lone ATP Tour victory came at Delray Beach, Florida in 2008.