First point to Murray as Zverev backhands into his net after a sumptuous return to the serve.

It's all on Zverev's first serve but it's a smash that just, just lands in that brings it to 15-15. Another superb return from Murray takes it to 15-30 and then another ridiculous rally, every shot looking like the winner, goes Zverev's way with a shank.

It's 30-30.

Zverev adjusts his sweatbands, one knee tapping away under his towel. Murray takes a long glug of water and wipes his face. Up they get and the Rod Laver arena applauds and yells. Here we go...

A double hander from Murray is excellently crafted and gives him the advantage, while Zverev looks at the court in dismay.

There's a bit of disagreement with the umpire about whether the ball hit the net - it's all terribly polite, given the situation - and then Murray slices into the net! Back to deuce. 

A close rally that goes Murray's way, charging to the net and slicing up and past Zverev, before his backhand lands in. He's held - and now Zverev will have to serve for the match.

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Evans gets on the board. But he's having to cover so much ground - we're going to see how much puff there is in the underdog as this one draws on.

Something lights up in Evans' head and suddenly he's a man possessed again.

40-0 down on the Tsonga serve, he recovers to deuce with a pair of hot-and-sizzle returns.

And now it's stamina, chase and gutsy tennis to win a break point, but twice he squanders advantage.

An umpire overrule saves Evans' bacon - another break point for the Brit. Gone.

Tsonga finally finds his nonchalant best and flips a drop-shot volley and then an ace for the game.

Brilliant from Murray, his fastest serve of the match, but he can't pick up from the baseline and that takes it to deuce.

Crafty old hand, is Murray, forcing Zverev to wait for his serve, but it's the German who is out on top with a superb volley, his quick hands digging it out.

A Zverev backhand from the baseline looks stonking but it hits the top of the net and dribbles back down. That's 15-15 and it's properly tense out there, even more so wen Zverev misjudges down the line.

The German hits the net again but this time it drops onto Murray's side. 30 all. Deep breaths now...

Lauren: Australian Open providing way too much tension for 7am on Sunday!

Gemma: I'm feeling almost sick with nerves right now.

Zverev lashes down the serve and Murray again knocks it into the net. Kid brother Alex looks suitably impressed.

And he'll hold his serve! Murray sprawls to meet the serve, can't control it and there's a huge roar from the Rod Laver Arena. Zverev is one game away from a proper upset.

Back on serve for Zverev and it's hammered in, before a dinky backhand at the net sends Murray the wrong way.

Murray doesn't make the same mistake twice, meeting Zverev's volley with his own bit of bish bash bosh, but that skiddy serve is into play again for 40-15.

Oh! That's awful! Zverev looks sure to have won the game with a set but he's smashed it into his own net! That's deuce. Dearie, dearie me.

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Tsonga is flexing his big, French muscles now.

Evans, 0-40, thinks he has the 12th seed beaten at least once with two tidy drop shots, but Tsonga plays splendid defensive tennis and the train is very much back on the track.

Evans, meanwhile, continues to be distracted by the stringing of his racquets. He seems to want a particular person to string it, and they don't seem to be about. Possibly popped off for a cuppa.

Russell Fuller
BBC tennis correspondent on Radio 5 live sports extra

Murray has been venting towards his box at the changeover and they will be hoping he can do something to turn this match around.

Murray's missing his backhand with an alarming regularity now but Zverev puts too much on a forehand that otherwise would have been a winner.

Up comes Zverev and back goes Murray, another hoick to take it to 40-15. Zverev is running all over the show and Murray holds as his backhand goes long.

The box stands up to applaud, all apart from Lendl, who just stands looking menacing. He'd be an excellent Bond villain. 

Mikey: The one night I stayed up late (2:35am here in Halifax, Canada) to follow Murray and he's struggling. Jinx alert! Come on Dan!

David: I can't take much more of this, time to step away from the radio and when I come back all will be well with two Brits in the last eight.

Evans just won't lie down.

He saves five break points but the sixth is a bridge too far.

Evans, as he sits down, seems to be complaining about the stringing of his racquet. He sends it back. disdainfully, for another stringing.

A stonker of a second serve from Zverev and Murray ends up meeting it with the edge of the racquet. Higher and higher it goes and Murray turns away from it in disgust.

The follow-up is just as good, flat and hard for a 40-15 lead. And that lofted shot from Murray again goes awry, rolling tamely into the net. The German will hold.

Bang! There's the ace from Murray, 205 km/h, but a gimme slice goes wide. There's been a lot of unforced errors today.

Up at the net now comes Murray and his drop shot comes off. It's right of the edge of the racquet but they all count. 

Another ace ends it. Murray holds but he's still a break down.

You may recall that Evans is buying his own T-shirts and shorts for the Aussie Open, after Nike decided not to renew his kit deal.

It comes with challenges.

"I've only got one shirt. The others are too tight," he shouts up to his box.

This is the last 16 of a Grand Slam, and we're watching a chap who can't find shirts that fit him.

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The clock ticks over to the three hour mark as Murray puffs out his cheeks, having ditched his cap. He can't meet a low backhand but a double fault takes it to 15-15.

A stunning backhand raises Murray's spirits but his return to a smash is rubbish, and he knows it. That angled backhand comes out again from Zverev, and Murray smashes into the net. Zverev holds - that was a poor return game from the Brit.

Jeremy Bates
BBC Radio 5 live sports extra

No signs of nerves from Evans all the way through that tie-break. No hesitation and incredibly aggressive. Tsonga is paying the price for being too passive.

Zverev and Evans are so unorthodox with their style that it gives their opponents different types of balls to assess. Different angles and spins, which asks a lot of questions.