Murray needs to address the second serve if he has any thoughts of wrapping Djokovic up in a permanent straight jacket. But in this game it ultimately matters little. Will the Scot wobble at 30-30? Nah. A 21-shot rally ends with a monstrous Murray forehand for 40-30 and the Briton is equally as emphatic in the next point, that brutal forehand making Djokovic look as if he has cement in his trainers.

A tired backhand into the tape from Djokovic followed by a tame netted forehand gives Murray hope at 15-30. And the Scot has two break points thanks to a Djokovic double fault - his first of the match. "Come on, Andy," says a gentleman in the crowd. A feather-light touch at the net from Djokovic saves one and on the next point Murray smacks an adrenalized forehand wide. Deuce.

But A third break point comes Murray's way and this time the forehand is on song. He swings loose and free until he lasers a winner into the corner.

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Jeff Tarango
Former professional tennis player on BBC Radio 5 live

On Murray berating himself: "Look at the statistics when John McEnroe used to blow off steam. In the next six or seven shots he'd win about 85% of points.

"Andy's letting is emotions get to him - in that he's forgetting how he won the US Open here in 2012. He's being supplying all the power to Novak so, on the run, Novak's been able to use that power to put Andy out of position. He needs to learn that balance between too upset and being fired up.

He's hitting great shots, but it's the wrong shot."

Djokovic the master craftsman. A beautifully crafted point as a delicious forehand tickles the line and forces Murray on the defensive...the Serb approaches the net and sees off the Scot for 15-15. A rattled Murray shouts something about his movement. "Collapsing" he screams towards his camp. He has two break points to save but is unable to stop Djokovic romping ahead. The Serb again works his way into a position to whack a fabulous forehand winner.

Djokovic plonks a backhand into the tape. A sniff for Murray at 0-30. Yelps of encouragement for both players from the New Yorkers. Is it a blip from Djokovic or cause for serious concern? The Serb screws a forehand into the tramlines. Three break points Murray. A meaty forehand earns Djokovic his first point of the game, but he's soon on the ropes - that trusty double-handed backhand doing the job for the Scot.

Murray's engine alternatively roaring and spluttering. For this game he's firing on all cylinders, holding to love. Djokovic content to maintain the advantage he has already got.

The points have shortened and Murray is going through one of his dips, spraying forehands to not only gift Djokovic a hold to 15 but present it with hundreds of thousands and a chocolate flake on top.

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Murray in trouble. He fails to negotiate the barrier, presenting Djokovic with two break points. The Scot embarks on one of his familiar monologues. "Idiot," he says, while shaking his head. His concentration floats away into the night sky and Djokovic clenches his first as he watches a Murray forehand slap into the tape.

Both players opening with comfortable service games. A hold to 40 for Djokovic.

Jeff Tarango
Former professional tennis player on BBC Radio 5 live

"That was a tough first set. I don't think Novak thought he was going to get the tie-breaker that easy."

Simon Laird: "It's a shame when you get a great game that's not the final...... It's only downhill after this thriller!"

Jamie Braithwaite: "Good sign that Murray isn't afraid to come out attacking against Djokovic, their friendship isn't getting in the way of an epic battle."

Murray left the court after the tie-break, perhaps for a comfort break or perhaps to look in the mirror and give himself an inspirational talking to a la 2012. Murray rattles off another game, holding with a thunderous ace down the middle.

Piers Newbery
BBC Sport at Flushing Meadows

"After Murray has a shocker in the tie-break, the crowd get to let off steam after 73 minutes of relative calm. 'Crazy dancing man', as he seems to be known, does his stuff in the stands to the sounds of Billy ldol. He's quite the character. They love him."

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Neither player deserves to lose the first set, but someone has to and it is Murray who falls behind. Five set points to Djokovic and the world number one is ruthless, his serve too hot for Murray to handle.

At 4-0 Djokovic is in control, but on the next point Murray ups the ante from the baseline and the Serb goes long. The Scot forcing the play, rashly stepping in from the baseline and goes wide. 5-1 to Djokovic at the changeover.

First point to Djokovic - 1-0. Double fault Murray - 2-0. A scooped backhand into the tape from Murray - 3-0.

Brutal and balletic. Hard-hitting from the middle of the court by Murray before he deftly volleys out of Djokovic's path for 15-15. But careless from the Scot as he allows Djokovic to pounce on a tame volley for 30-30. But he comfortably sees off the Serb, who nets a forehand and is then forced to watch an ace fly whistle by. I suppose we might as well go to a tie-break...

Breathless stuff. Djokovic drags Murray towards the net with a cushion-soft drop shot, but the Scot is alert and his reply forces Djokovic to volley wide. Murray again at the net, putting Djokovic under pressure, but such is the venom of the top seed's strike, Murray can do little but launch the ball of yellow felt into orbit. What have you got, Andy?

A shrug of the shoulders from Djokovic as he goes long for 40-15, as if to tell his camp "there's nothing I do". A dreamy forehand from Murray to conclude a convincing hold.