Kyle Edmund flattens a crunching backhand across court to bring up 15-40 and two break point.

"Well done Kedders," shouts Leon Smith from the sidelines.

Edmund tries the same trick on the next rallym, but finds only the net.

Guido Pella chalks off the second break point with the first ace of the match.

Guido Pella, at the sixth time of asking in this match, finally breaks Kyle Edmund's serve.

You are going to struggle to force a cigarette paper between the two of these.

The captains could tip the balance in a tight match between two largely inexperienced players and Leon Smith is rabbiting away to Edmund at the changeover.

Image source, Reuters

John Lloyd
Former GB Davis Cup captain on BBC Two

Kyle Edmund has major weapons. He has a very good first serve but the forehand, we saw Del Potro, this man has a huge forehand too. 

Mentally he has been much tougher, being around the Davis Cup team has improved him. 

I think he is going to be a top 20 player.

Guido Pella gets on the board belatedly, holding to love.

This is the tale of the tape between those two. It feels like Pella is close to maxing out his potential, while Edmund may have a little more nitro in the tanks to climb up the rankings.

Jamie Baker
Former GB Davis Cup player on the BBC Red Button

You won't see anything special from Pella, like the Edmund forehand, but he will be difficult to beat.

"Super Kyle Edmund," chant the Glasgow crowd.

 It is a blaster v grinder vibe out there.

The Briton is the man with all the big shots. Pella is banking on scurry, heart and street smarts.

Image source, Getty Images

All square in the other semi-final...

Jamie Baker
Former GB Davis Cup player on the BBC Red Button

What a great start for Kyle. 

What a bonus to lift the crowd, his team, everyone.

First blood to Britain.

Guido Pella surrenders the break with a double fault, his second-serve swerving wide of the T.

Image source, Reuters

Kyle Edmund holds Guido Pella at bay, defending four break points across the whole of the game, to get on the board.

These two look as evenly matched as we expected.

John Lloyd
Former GB Davis Cup captain on BBC Two

Kyle knows in back of his mind if he were to lose then Britain would be 2-0 down with Del Potro coming in in the final match.

Argentina would be big, big favourites if Kyle loses this match.

Kyle Edmund is straight into an arm wrestle of a opening game, seeing off break points to claw his way back to deuce.

I hope the Emirates Arena bars have got their late licence for tonight.

Image source, Reuters

Edmund to serve as the Emirate Arena patrons make their way back to their seats.

So how do Edmund and Pella match up?

They have faced each other just once before, with Pella prevailing 7-5 in the final set of their meeting at Indian Wells earlier this year.

Edmund served for the match in that one.

Edmund is ranked 55th in the world, Pella is 49th.

Captain Leon Smith apparently thinks that this nippy Glasgow court will suit Edmund's big forehand though and that could be the decisive factor.

John Lloyd
Former GB Davis Cup captain on BBC Two

Kyle Edmund was going into this match thinking he was 1-0 up but now he is down 1-0.

He knows he has to win this match, the whole dynamic has changed.

Everyone ready?

Legs stretched? Mugs recharged? Sense of time, space and the limits of human ability restored?

We have the second singles rubber coming right up.

Kyle Edmund emerges from behind the scenes - looking a little nervous it must be said - to face Guido Pella.

John Lloyd
Former GB Davis Cup captain on BBC Red Button

I can't remember many matches being better than that. The atmosphere, the drama. Both players were exceptional. 

Murray looked dead on his feet after two sets, after the personal stuff going on and the year he has had but he got a second wind. 

Both players deserved the standing ovation.

Del Potro's forehand was one of best forehand performances I have ever seen in a match. He over powered Murray at times, it is one of the biggest shots in the game today.

Gareth Cartwright: Shame that Murray couldn't put GB 1-0 up but it's so great to see Del Potro back at this level again. Incredible match!

Tom Gumbleton: Great match from both @andy_murray & @delpotrojuan that was some incredible tennis

Kenny Simpson: For the 2nd tie in a row, Kyle Edmund has to step up!

The match had everything: Murray magic, delicious Del Potro forehands, and even a couple of hot dogs! Click play below to see Juan Martin Del Potro overcome Andy Murray with an ace and put Argentina one-nil up in this Davis Cup semi-final.