ANDY Murray continued to blaze a trail through the Australian Open draw but the world No 5 accepts tougher challenges lie ahead as he bids to land a maiden grand slam.

Murray cruised past Jurgen Melzer, winning 6-3 6-1 6-1 in an hour and 44 minutes to maintain his record of having not dropped a set in the tournament so far.

The British No 1 produced a mature, controlled performance, contrasting sharply with that offered by Melzer, the Austrian spraying the ball all over Rod Laver Arena.

Murray will meet Alexandr Dolgopolov in the last eight after the Ukrainian stunned fourth seed Robin Soderling in a five-set thriller.

And with Rafael Nadal and Roger Federer potential opponents in the semi-final and final, Murray accepts straight-set wins may be a thing of the past.

He said: ‘‘I feel good but the matches are definitely going to get tougher.

‘‘I’m not expecting to go through the tournament winning matches like that, with that scoreline. So I’m ready for that mentally when it does get tough.’’ Murray again got off to a good start, as he has done in the majority of his matches in Melbourne.

‘‘I started very well, hitting the ball very cleanly right from the beginning of the match,’’ he added.

‘‘There was a few games where it was tough from one of the ends. It doesn’t feel it when you’re watching, but all the players will tell you from the far side of the court, it is difficult. I came through a couple of tough service games from that side.

‘‘But when I had the wind with me, I dictated a lot of the points, returned very well, served well in the second and third sets. So it was very good.’’ Having lost the break and then regained it in the first set as Melzer struggled, Murray served it out and then struck early in the second by cracking a forehand cross-court winner to break.

Murray threatened again at 3-1 as Melzer’s frustration began to mount.

The Viennese saved one break point but then gifted Murray another with an awful backhand into the net, prompting him to slam his racket on to the court.

Murray, who was cheered on from the players’ box by comedian Billy Connolly, also had cause for complaint when on the next point he appeared to clinch the break when he hit a clean winner off a ball which was called narrowly out. Melzer appealed and the ball was found to have caught the line meaning the point was replayed.

And when Melzer won it, Murray sarcastically offered a thumps up to the linesperson.

It ultimately mattered little as Murray claimed the break anyway after using his irritation to good effect.

A comfortable hold and a break to 15 then saw the 23- year-old move two sets up.

Melzer suggested he may be getting his act together at the start of the third as some fine hitting from the back of the court set up two break points.

But Murray wriggled back to deuce before sending down two big aces.

And the writing was on the wall for Melzer when some more wayward hitting enabled Murray to break for a 3- 1 lead shortly after.

That quickly became 5-1 as a routine hold was followed by another break thanks to a stunning pass as Melzer approached the net.