British women's number one Heather Watson on Twitter:, external I'm so tired just by watching this tiebreak. Every point is epic.

Andy Murray is chuntering along to himself as he wipes his furrowed brow at the break. Any ideas what he is saying to himself? Who knows. Ready for another set? Good....

Piers Newbery
BBC Sport at Melbourne Park

If you play the world number one for 20 minutes and he doesn't make a mistake, you've done pretty well to make it to a tie-break. This is video game tennis on the hardest setting imaginable. The wind is still gusting and making it tough to serve from one end, there are a few heavy clouds visible in the darkening sky above, and we could have another four of this to go.

Anna Langton:, external I feel like I'm watching something of historic significance. Amazing tennis.

Grumpy-old-man:, external Currently in hospital watching the final, got excited shouting 'come on', nurses came running to save me.

Robin Armstrong:, external Can barely watch. Watching and then looking away. And there may be four more sets after this.

Image source, Getty Images

Set point Djokovic. An ace down the middle? Nope, although HawkEye proves the Djokovic serve was a only a fraction wide. Murray with a backhand return into the net on the second serve and Djokovic clenches his fist. I shall pass you on to Jonathan 'JJ' Jurejko who will guide you through the second set.

'Ooohs' and 'aaahs' fill the Rod Laver Arena as lobs and smashes are brought into the mix. But then Murray misses a simple volley at the net - to give Djokovic a set point...

The spectators burst into life, whistling and screaming encouragement to their favourite player before Murray serves up. Murray pouncing like a panther at the net - a driving crosscourt winner. Beautiful.

Image source, AP

This is tense. Very tense. And it is getting to the players. Another error from Murray, overcooking a backhand from the baseline and Djokovic claws back a 4-2 deficit to lead 5-4.

Djokovic long on the first serve... Second serve finds the target... both holding firm at the back of the court until a Murray forehand dribbles into the tape and we're back on serve.

Murray changes ends with a two-point lead. The Scot serves to extend that advantage, pumping a first one wide. Don't double fault Andy, don't double fault. He double faults. An aggressive second serve misses the target.

Limbs are tightening, the brain starting to play games as we reach squeaky-bum time. Another mammoth baseline rally and Djokovic, sliding along the back of the court, nets a forehand.

Another long rally - and another break! Murray nudges ahead as a loose Djokovic forehand goes long.

Djokovic breaks back. Murray's second serve is returned with interest from Djokovic, sparking a 20-shot rally. Murrays look to end it with an ambitious lob - too long.

Djokovic has wiped away Murray's mini-break and follows up a fine first serve with a winning backhand volley to level at 2-2.

A rasping serve down the 'T' from Murray followed up with a dreamy forehand winner. Murray 2-0 up.

Ding ding! That's the sound of the tie-break bell.

Djokovic to open up, first serve down the line. The second? Too long. Double fault from the world number one. Wowsers.

Pat Cash
1987 Wimbledon champion on BBC Radio 5 live

"One of the major improvements in Andy Murray's game has been his movement around the net."

During the changeover Murray complains to the umpire that comings and goings near one of the entrances to the court are in his eye line so a man in a suit trots on and off to deal with the situation. Feather-soft touch at the net from Murray, a backhand volley, brings up three game points. A crafty first serve later, Djokovic netting the return, takes us to a tie-break. Yay!

Andrew Castle
BBC tennis commentator on BBC One

"Tennis is often about concentration. Just when you think Djokovic is losing concentration he clicks back in. Now Murray is back under pressure, serving to stay in the set."

Crash. Bang. Wallop. That's the sound of Djokovic launching a bazooka down the 'T' with such power that there's a thudding sound as it hits the back of the court. Murray nicks two points, but an angry forehand volley into the corner from Djokovic brings the game to an end. And what is that on appearing on the horizon? A tie-break?