Preview: Roger Federer v Andy Murray

Andy Murray goes head-to-head with 17-time Grand Slam winner Roger Federer on Wednesday morning - but who will come out on top?

Novak Djokovic's quarter-final loss to Stanislas Wawrinka has well and truly opened things up in Melbourne.

And what better motivation for Roger Federer and Andy Murray as they go head-to-head in their quarter of the Australian Open.

The tournament Down Under is now guaranteed to have a different winner for the first time in three years - and both Wimbledon champion Murray and four-time Australian winner Federer have as good a chance as ever to make the title their's.

That may be hard to believe with 17-time Grand Slam winner Federer - but the 32-year-old has found renewed vigour in 2014.

“I don’t have doubts any more,” he told reporters this week. “For me, personally, I’ve ­overcome it. I know I’m going ­definitely in the right direction.

“This match against [Jo-Wilfried] Tsonga was a big test for me. I don’t need Murray to have a further test.

“What I’ve shown over the last three to four months to myself is that I’m more confident, that I know I’m most likely going to play OK in my next match, which wasn’t always the case midway through last year, when I didn’t know how I was going to feel during the match.

"We are both coming into this match with a good feeling.”

That win against Tsonga was the undoubted high-point for Federer in a tournament which has seen the Swiss get to the quarters without even dropping a set. Clearly, hiring Stefan Edberg as his new coach late last year has provided Federer with enough momentum to return to form.

But is he back to his best? The truest test of that will come against Murray, who - for his part - is ready to face his old nemesis.

"I've played him around 20 times," Murray said after his fourth-round win over Stephane Robert. "You know how you need to play against him - and you know tactically the things that work and the things that don't work."

Murray's form, though, hasn't been as impressive as you'd think. He dropped a set against Robert - and even broke his racket in frustration. It might be understandable given his injury problems, though the Scot will still be aiming for his absolute best.

It's Murray that leads the pair's head-to-head record 11-9, with the 26-year-old also winning the duo's clash at last year's Australian Open semi-final.

But it might just go to the wire this time. And, for the first time in a long while, a clear favourite is very hard to find.