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So, it comes to this.

This will be Rocky I, II, III & IV (not the rest), Return of the Jedi and possible the last The Hunger Games all mixed together.

The ultimate climax.

For the first time the destination of the men's singles world number one spot will be decided in the final match of the season.

I'm not going to type 'you couldn't have scripted it' - ahh, I just have.

All it remains me to say is join us on Sunday for live text, audio and TV coverage for the Battle To Be Number One.

Winner Novak Djokovic: "I started off very well and got a 4-0 lead and I pretty much excuted everything I tactically planned to do. That helps when you are playing a top player. Kei was obviously tired and not at his best tonight.

"My level had been going in the right direction. I'm very glad I get to experience this feeling on the court. Now it's coming up to the last match of the year. The match everybody anticipated. I hope we get a great final."

On the battle for number one against Andy Murray on Sunday: "There's two of us on the court so let's try to be able to enjoy the occasion.

"This has never happened in the history of tennis. I'm privileged to be part of the history. This is one of the biggest matches we will ever play against each other."

Image source, Rex Features

Here's a stat - Nishikori has won 48% of points on his first serve. Not good.

Djoko on the other hand is at 82%. He wins this service game to love and is one away from victory and a place in the final.

Nishikori is one point away from winning a game on his serve!

He's only gone and done it. It's taken him 57 minutes.

I wonder if he'll find some sort of solace in that? 

Image source, EPA

You know the way Djokjovic played to win his 12 Grand Slam titles...?

Anyway, Djoko slaps a forehand winner like Level 42's Mark King slaps his bass to move 40-15 up.

He holds as Nishikori's return is too long. He's only two games away from a stunning win.

Image source, Reuters

Nishikori has yet to hold serve - he's facing another two break points. 

Here's a towel pal, if you want to throw it in.

But wait two good serves brings it back to deuce. But then a wayward backhand from the world number five gives Djoko another break point opportunity.

And astonishingly the Serb breaks again as he sticks his racquet out and somehow returns Nishikori's serve, seemingly surprising the Shimane-born player.

Steamrollered.

Image source, Reuters

Djoko holds after Nishikori returns a forehand into the net. An important hold for Djoko after breaking.

The world number two has just moved the gear stick into Cruise.

Sorry, a bit Partridge.

Image source, EPA

Nishikori - who unlike Andy Murray - has had more success with his challenges this week, challenges a Djoko return which is judged in. It was Kei, it was in. Sorry.

It's 15-30.

Then 15-40 after Nishikori's trusted backhand down the line fails him.

The players follow that up with a demonstration of top-notch stretching with Nishikori coming out on top. One break point saved.

But Super Novak takes the second opportunity.

Nishikori is broken yet again, for a fourth time.

If the earlier singles match was like two heavyweights in the ninth this is like scrappy middleweight clash on the undercard, with one fighter doing just enough to win the rounds.

That fighter is currently Djokovic but he is having to scrap too having been 40-0 up to have it pulled back to deuce.

Nishikori then fires down a stunning winning return down the line - it's break point. Unbelievable really.

Break point saved with an ace.

But yet another beautiful double-handed backhand down the line from King Kei sets up another break point.

Djoko saves with an ace - again.

The Serb then serves out to seal the first set.

Image source, Reuters

It's error o'clock from both players at the moment. Djoko has a 30-15 advantage but he should have put away a forehand at the net.

Super Novak then puts Nishikori in a corner before coming into the net and smashing a return out of the reach of the Japanese player.

Djoko breaks again after a stunning lob lands inside the far corner and Nishikori's smash finds the net.

He now serves for the first set.

Image source, AFP

Djoko fires a forehand into the feet of Nishikori - 30-15.

Nishikori then tries to find a winner down the line but finds the net - 40-15.

All over? No. 

Nishikori does manage a winner down the line before Djoko makes an error. Yes, an error. It's deuce.

What do we have here? Advantage Nishikori after another error from Djoko who puts too much on a backhand.

Another error sees Nishikori pull a break back.

Weird, this tennis!

Image source, Getty Images

This is worrying for Murray - Djoko looks as good as he has all year.

A great first serve at 0-30 is picked up by Djokovic who runs full pelt towards the net, slides and makes the return winner.

Nishikori pulls it back with an ace before Djoko breaks the Japanese player again.

Image source, AFP

Djoko fires down a 100mph-plus second serve to baffle Nishikori and go 30-0 up.

The defending champ then smacks down a fierce first serve to seal his second service game.

He looks more relaxed then a Euromillions winner sipping water out of a coconut on the Cayman Islands.

Djoko has another break point - will he convert this time?

He does thanks to Nishikori's double fault.

This might be a long night for Nishikori - or short one, I guess.

After that minor delay, we continue.

Sadly for Kei Nishikori it doesn't upset Djokovic's rhythm nor does it improve his as he makes two more unforced errors.

However, he pulls the scores back to 30-30 then produces an ace. 

It moves to deuce before another error by the Japanese player and a winner from Djoko hands him break point. However, Nishikori saves with a stunning shot down the line.

A deuce battle ensues...

Image source, Reuters

Somebody tries to get on to the court but is rugby tackled by the alert security guards.

Nishikori has made two unforced errors from the back already. The Japanese world number finds the net again before Djoko wrongfoots his opponent with a double handed backhand winner.

Textbook opener from the world number two.