Good evening and welcome to our LIVE coverage of the second semi final of this year's ATP World Tour Finals between Novak Djokovic and Stanislas Wawrinka.

So it's the world number one versus the world number two in tomorrow's final. Rafa versus Novak in what promises to be a pulsating encounter. Join us again at 8pm GMT to see who is going to be crowned the end of year champion in what will be the 38th showdown between two icons of the game.

DJOKOVIC 6-3 6-3 - GAME, SET & MATCH! The defending champion marches into the final, taking his unbeaten run to 21-matches. The Serbinator's returns have been too good tonight and he racks up two match points with a run to the net that forces Wawrinka to fizz long. The Swiss buckles once again and when he crashes a shot well wide of the baseline, Djokovic is literally left to jump for joy.

DJOKOVIC 6-3 5-3 - There are no cracks in the Djoker's armour as he wraps up another service game with relative ease. Not even an unfortunate net cord can halt his momentum as Wawrinka's chances fade when he slams a shot down the line into the net at 30-15. Another relentless rally ends with the Swiss miscuing under pressure and he's left serving to stay in it now.

DJOKOVIC 6-3 4-3 - Once again Stan is made to work very hard to stay in this set. At 30-30 he finds some respite with a timely ace before Nole fires a return long.

DJOKOVIC 6-3 4-2 - While Stan is forced to pull off minor miracles to hold serve, Djokovic is barely breaking sweat. Another sublime touch at the net puts him in command at 40-0 and Wawrinka then fires long to end the game all too quickly from his point of view.

DJOKOVIC 6-3 3-2 - Gritty stuff from the Swiss number two. Wawrinka is forced to face break points for the fourth successive service game. A beast of a backhand winner gets him out of jail briefly but he is forced to save another before an ace puts him in control. Nole then produces a ridiculous winner on the run when he looked dead and buried to tie it at deuce again. But Stan digs deep and somehow stays focused to survive.

DJOKOVIC 6-3 3-1 - The Serbinator continues to dictate the rallies dragging Wawrinka all over the court and forcing the errors. He's not having to hit many winners tonight, but he's still well on course for the final. A touch of finesse with two delightful drop volleys prove decisive as he takes the game to 15.

DJOKOVIC 6-3 2-1 - With Wawrinka on the rack, Nole steps on the gas by forcing the Swiss to go for some tough winners on the back of some bruising rallies. The world number eight is being pulled from left to right and then back again, leaving him exhausted and prone to some wayward forehands. It tees up a double break point but he keeps fighting back and saves both before going on to take the game when Nole fizzes long. That ends a five-game losing streak for the Swiss number two.

DJOKOVIC 6-3 2-0 - Relentlessly efficient. That's how to consolidate the break. A thumping second serve ace claims the game to love. It's looking bleak for Wawrinka.

DJOKOVIC 6-3 1-0 - BREAK! The worst possible start to the second set for Stan sees him hand the initiative to Nole. The Serb's returning is proving too hot to handle for the man from St Barthelmy and it results in three break points. To his credit, Wawrinka saves two of them with some brave hitting but he eventually succumbs with a wide backhand. Those rallies really are punishing.

DJOKOVIC 6-3 - SET! Stan the Man is going toe-to-toe with the world number two but can't quite deny Nole the set. The Swiss is having to go for more and more shots, resulting in a mixed bag of errors and exquisite winners. It sees him notch up a break point, but a mistake on a sliced approach shot lets the Djoker off the hook. The defending champion then fires in a winner and gets the right result on a challenge that sees an ace conclude the set.

DJOKOVIC 5-3 - BREAK! Wawrinka's low first serve percentage is starting to cause him problems and a 16th unforced error into the net tees up two break points for Djokovic. An epic rally sees the Serb fizz an uncharacteristic forehand into the net before some incredible defensive play keeps him in a point he looks destined to lose. Wawrinka then smashes a forehand too low and leaves the Djoker to serve for the set.

DJOKOVIC 4-3 - There's no change out of Djokovic this time around either as he ruthlessly surges through the most routine game of the match so far to take it to love. A beautifully angled shot to trump Wawrinka's pinpoint return is the pick of the points. Just the five unforced errors from the Serb at this juncture.

DJOKOVIC 3-3 - Djokovic tweaks a string and is forced to change rackets at 40-0. It briefly disrupts Wawrinka's rhythm but he regains his composure to secure a comfortable service game to 15.

DJOKOVIC 3-2 - Brilliant tennis from the Serbinator. The machine's gears are warming up nicely now and a sublime crosscourt winner at the net puts him in the ascendancy. The rallies are starting to turn the way of the reigning champion and he sees it out to 15 when Wawrinka fires long.

DJOKOVIC 2-2 - BREAK! Hugely disappointing for Stan. He tries to consolidate the break but finds Novak in determined mood. A stunning return stumps the Swiss after he had fizzed down a 134mph serve. It's clear the world number eight feels he has to go for his shots but he fires long at 30-30 to give the Djoker the chance to break back - and a howler of a miscue flies well wide of the tramlines to gift him just that.

DJOKOVIC 1-2 - BREAK! No fear from Wawrinka as he continues to attack the Djokovic serve and this time it pays off. A sensational backhand winner across court puts him in control at 0-30. The Swiss then wastes a break point at 30-40 before clocking up a second with a magnificent crosscourt winner with Nole attacking at the net. It's a crucial point and he makes it count with some great tactics that ends with him flashing an angled volley into the open court to claim first blood.

DJOKOVIC 1-1 - A shot down the line at 40-30 is called out and the challenge shows there is less than a millimetre in it. It gives Djokovic a foothold in the game at deuce but an ace restores Wawrinka's confidence and then a wide first serve proves too good.

DJOKOVIC 1-0 - The Serb fires a forehand wide of the right-hand tramline in the opening point and follows suit just seconds later to give Wawrinka an early chance at 0-30. The Swiss then cracks a shot low into the net before firing just long after going for the winner. It allows Djokovic a reprieve and he forces an awkward slice from Stan which is followed by a forehand down the line that smashes into the net. Great defensive play by Nole.

The pre-match is done and dusted. Time for the main event. Djokovic to get us underway with the first service game.