Good aggression from Murray, who volleys for the first point on his serve.

Three more to go, but a bullet backhand by Tsitsipas puts the Briton on the back foot and he can't recover. 15-15.

Francesca Gunn: I’m actively not watching the Murray match every time I turn it on to check the score Andy starts losing points. I’m helping him win guys.

Laura Robson
Former British number one on BBC Radio 5 Live Sports Extra

I think Tsitsipas is waiting for Andy's level to dip and for the energy to drop.

I still expect it to happen at some point. I think it's going to be really tough for Andy to keep this level through the whole match.

There is still so long to go.

A couple of forehand winners keep Murray alive and kicking in the game, but Tsitsipas gets over the line at 40-30.

Time for Murray to serve for the third set.

This is special from Murray. Considering where he has come from, to find himself in this position against the world number three at a major is a magnificent effort.

There's a long way to go yet though. Tsitsipas eases into his serve and a confident forehand makes it 40-0.

David Law
Commentator on BBC Radio 5 Live Sports Extra

Murray seems to be uplifted by his own form. His own ability to do what he wants to do on the tennis court in goodness knows how long.

Laura Robson
Former British number one on BBC Radio 5 Live Sports Extra

Andy could not be playing any better. It is vintage Andy Murray.

We haven't seen this in so long and how good it is to watch.

A forehand winner and an ace help Murray on his way to a 40-15 lead as he edged towards the third set.

That will do nicely! Murray draws Tsitsipas into the net before placing a backhand volley beyond the Greek for 5-2.

Laura Robson
Former British number one on BBC Radio 5 Live Sports Extra

Andy has not won at this level in such a long time. You expected that he wouldn't have the energy to keep going here.

He is absolutely still in control of the match. He looks a bit more tired than Tsitsipas but I think he just shows it a bit more.

David Law
Commentator on BBC Radio 5 Live Sports Extra

This has been special so far. Has it got a special ending for Andy Murray?

I am amazed that Murray has kept it up this long. His level has not dipped at all.

Stefanos Tsitsipas remains just the one break`behind, of course, but this scoreboard looks very good for Murray.

We knew he'd make a fist of this, but he's exceeding all expectations so far. It's back over to the Brit sharpish, however, as Tsitsipas fires an ace for a hold to love.

A forehand winner keeps Tsitsipas in this marathon fifth game in set three, but Murray responds with a forehand of his own to take control once more...

And this time he completes his escape! A fine backhand drop shot seals a crucial hold for 4-1.

Laura Robson
Former British number one on BBC Radio 5 Live

The first-serve percentage from Andy Murray has definitely dropped.

You have to think that is down to the amount he has put through his legs today and we are only at the start of the third set.

Image source, Getty Images

David Law
Commentator on BBC Radio 5 Live

I've missed this. Andy Murray going bananas at himself between points.

A FOURTH break point for Tsitsipas, can Murray stay alive again?

Of course he can! An ace denies Tsitsipas, who then finds the net to hand over a game point.

A huge serve from Murray takes us back to deuce. This really is a great battle.

Murray survives a second break point, but he'll have to save a third as Tsitsipas mixes things up with an excellent sliced drop shot.

Big, big moments in this match, and Murray rises to the occasion with an ace to force deuce.

Tsitsipas sets up another chance to break back with a smash, though.

Laura Robson
Former British number one on BBC Radio 5 Live

I'm really impressed with how calm Tsitsipas has stayed. He has been more consistent and all of a sudden this is his chance to get back in set three.

Tsitsipas pegs Murray back to 30-30 with a sublime whipped forehand as the third seed seeks a route back into the set.

And the Greek takes full advantage of a second serve to set up a break back point...