Nip and tuck this game but then... Isner fires wide at 30-30 and it's another matchpoint, the fourth in total, for Ward.

But once again Isner saves it, thanks to a massive first serve. Deuce. But Ward rips a backhand over the net and secures a fifth matchpoint. Maybe this time?

Er, no. Isner - and you have to give him great respect for this because he looks exhausted - hits back and takes the game. 11-11. Ward to serve.

Harry Waldie: The noise will be immense if (when) Ward wins this.

Indeed. We're in Salford and we can almost here the racket (no pun intended) from here.

A lengthy game with a few nervy moments but Ward wins it to restore his advantage and take it to 11-10.

Hang on, where's he going? As the game ends he races from the court into the bowels of the arena. Appropriate description that for it looks like he's nipped to the loo.

Whatever he got up to, it didn't take long. Ward is back, and we begin the 22nd game of this marathon fifth set.

A lot of Twiiter talk about Jamie Ward's shirt.

What do you reckon? And given how he's playing, does it matter?

Image source, Getty Images

Alban Lee: This is unbelievable!

No, it's really happening Alban. Honest.

Hang on. An incredibly limp backhand from Isner puts ward 15-30 up. Two points from the match. Nice serve and volley tennis from isner brings him back to 30-30 though, and means he avoids getting in a distinctly sticky position.

It goes to deuce. And Isner puts a forehand wide. It looked easy. but when you're shattered.

Ward waves his hands and the crowd goes berserk.

Matchpoint. Saved. Or missed to be more accurate - a mishit Ward forehand dropping just long with Isner static at the net.

Back to deuce. And Isner powers through to just about hold again. How many times have we said that this set? A lot. It's 10-10, fifth set.

Image source, Getty Images

Isner holds but it's a case of anything you can do...

Ward might be 111 in the world but he is playing inspired stuff. Big ace to make it 10-9 and its Isner to serve next to stay in the match.

Remember, victory for Ward would put GB two-up after Andy Murray's earlier win. and put them in pole position to win this Davis Cup tie.

Amanda Elliott: This is epic... 8-8 in fifth what a great effort from Ward. Isner upping his level a bit though I feel.

Ben Dalton: Lest we forget, John Isner has some decent history in long fifth sets.

Indeed Ben. You have got a sleeping bag handy haven't you?

Oscar Snow: James Ward's shirt makes it look like he's just rocked up at a BBQ and fancies some tennis. Love it!

Watch it Oscar, if he wins that's the best shirt we've ever seen.

Andy Murray jumps to his feet and pumps his fist as John Isner slams a weak-looking forehand into the net and Ward holds serve.

So did Isner, so we're at - hang on, hand me a calculator - 9-8 to Ward. On we go. Isner to serve. Quiet please.

Some footie. We brought you the breaking news earlier that Manchester United defender Jonny Evans has denied an FA charge for allegedly spitting at Newcastle's Papiss Cisse in Wednesday's Premier League match.

Image source, Getty Images

You can read the full story here.

Piers Newbery
BBC Sport at Emirates Arena, Glasgow

"The Isner backhand has all but left the building, but the world number 20 is doing enough with his serve and forehand to stay alive.

"Ward has been playing the better tennis for the last two hours and should be fit enough to go for some time yet, having spent some of the off-season training with Murray in Florida."

What's that? You'd like a sort of general overview photograph of the arena but with a British flag somewhere in the foreground?

Sure thing.

Image source, Getty Images

Ward holds. He's 8-7 up. Pressure back on John Isner.

Both players hold serve, first Ward, then Isner.

The score moves to 7-7. Gripping stuff.

Ruth Corrigan: Superb play from James Ward no matter what the outcome!

Andrew Lawton: Huge tennis from James Ward. Incredible performance he's putting in at the moment.

Ed Fondue: Whatever the result James Ward has been immense. One of the best GB Davis Cup performance.

Remember this?

Image source, Getty Images

We really could be here all night. Can anyone bring me some sandwiches and a nice milky coffee?

Isner, to his great credit, holds well, despite losing the first point of the game when James Ward produced a thumping forehand.

It's 6-6. No tie-breaks in the fifth set, which means we could still be here tomorrow morning.

Ward holds again with relative ease. He leads 6-5. The Brit definitely looks the stronger.

Fascinating game coming up now, especially given how much Isner has been struggling to hold serve of late.

Don't go anywhere.

Piers Newbery
BBC Sport at Emirates Arena, Glasgow

"Ward has the beating of Isner when he can get the 6ft 10in American on the move, something Andy Murray appears to have been relaying to captain Leon Smith on the sidelines.

"Murray has also been signing autographs and took a few moments to himself in the nearby facilities, which are actually reserved for the media. We'll let him off though."

Image source, Getty Images

Let's break away from the tennis for just one moment and news that there is no sign of a British charge at the WGC-Cadillac Championship, external in Miami.

Adam Scott has, however, started day two well and is four under through nine holes, six under overall.

JB Holmes leads on 10 under. Welshman Jamie Donaldson and England's Lee Westwood are nine off the pace.