Wawrinka roars to the crowd as he breaks Evans to lead 5-3 in the second set.

Evans is 40-0 up but lets the Swiss back in with some sloppy serving.

Wawrinka then rattles through his service game to love and that's the set and we're all square at one set all.

Image source, EPA

Paolo Lorenzi will have run the rubber off the soles of his shoes tonight.

The Italian - eyes on stalks, dripping with sweat - is like a bloodhound hunting down every ball and keeps within range of Murray in the fourth.

Andy Murray comes through an arm-wrestle of a game, grinding his way through Paolo Lorenzi's spirited resistance.

Is that the last dregs of fight wrung out of the Italian?

He seems to have bottomless pits of grit.

Image source, Getty Images

Stan Wawrinka is having his left ankle checked out, having twisted it two games ago.

Here comes the magic spray, followed by a big blue bandage, and plenty of tight strapping. How's he going to get his trainer back on?

Meanwhile, Dan Evans, waiting for his turn to serve, is complaining he is being denied time to go to the toilet.

It's all happening...

Gregor: What's the odds on a Murray v Evans semi..... With Edmund waiting on the winner? Or have I had too much wine?

Andy Murray is trying to bury the embers of Paolo Lorenzi's challenge under a pile of points.

He forces his way to deuce, works up one break points, and a second with a whipcrack backhand across court and watches Lorenzi's lob drift long over the baseline.

Image source, AP

Dan Evans continues to flourish against Stan Wawrinka, making the third seed run around like he's the boss.

The Swiss twists his ankle and falls to the ground, but he's up quickly and after a little rub and a quick shake of his joint he's back in action.

It's getting lively out there, there's a cracking atmosphere, as the fans sense a shock could be on the cards.

Image source, Reuters

Jamie: It's taken him a while but @andy_murray, external finally looking like the tournament favourite - and he's had to against Lorenzi

Andy Murray's ninth ace of the match ties up the third set.

Paolo Lorenzi is looking at a pretty unpalatable scene now.

Murray just swept that set from under his feet and disappeared over the horizon.

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Paolo Lorenzi sees off a set point to keep his cards on the table in the third.

But this is going to take something more Dynamo than Deadwood to keep him in this.

Andy Murray holds to love. Paolo Lorenzi suddenly struggling to find the answers that flowed so readily in the first two sets.

Image source, AFP

Andy Murray hits a flourish of a forehand away to move 15-40 up and Paolo Lorenzi chunks a backhand into the net on the next point to hand over the double break.

It feels like this might be Murray moving up a gear just as Paolo Lorenzi begins to drop down the revs after red-lining it all the way so far.

David Smith: It's just struck me that Dan Evans looks like Jonah Hill from 21 Jump Street. Now it's all I can see.

You can tell him David.

Image source, Getty Images

Dan Evans has done it! The Briton seems to be relishing the occasion and takes the first set 6-4 against the third seed Stan Wawrinka.

Evans on top of his game with just eight unforced errors while the Swiss seems to be struggling with his serve.

Image source, AFP

Lord Camomile: Lordy goodness, Murray clearly out of sorts but credit to Lorenzi throwing some bombs over the net too!

Matt McGladrigan: Didn't get to see a ball of Murray's first two dreamy matches. But, sure, I get to suffer this delight of a contest.

Andy Murray goes for a bathroom break, perhaps trying to locate the mirror moment that inspired him to his breakthrough Grand Slam win in 2012., external

He comes out popping and holds to love to keep clear.

Over on Louis Armstrong, Dan Evans has broken Stan Wawrinka's serve and leads 5-4 in the first set.

Wawrinka is furious, throwing his towel down in disgust, and slumps into his chair.

Evans, meanwhile, prepares to serve for the opening set.

Image source, AFP

Paolo Lorenzi digs in deep and bails himself out of a spot of bother.

Andy Murray still cannot get clear blue water on the scoreboard.

Paolo Lorenzi is proving as tough to shift as carelessly-discarded chewing gum.

The Italian fights against the tide, pulling himself clear of 15-40 and back to deuce.

Image source, AFP

Andy Murray holds serve to back up the break.

Whatever the result from here - and the world number two is still a big favourite - there is going to be some meat to pick off the bones of this display.

Murray seemed distinctly underwhelmed by the support coming from his box as well judging by his reaction at the end of the second set.