Good afternoon and welcome to our LIVE coverage of the Group A showdown between Rafael Nadal and Stanislas Wawrinka at the ATP World Tour finals.

The victory ensures Nadal will end the year as the world number one. It wasn't vintage stuff from the Spaniard but he took advantage of Wawrinka's inability to make his chances count. Rafa marches on to the semi finals leaving Wawrinka to fight it out with Berdych and Ferrer to claim the other qualifying spot in Group A.

NADAL 7-6 7-6 (8-6) - GAME, SET & MATCH! Nadal races into a commanding 3-0 lead in the tie break but is soon pegged back by the resilient Wawrinka who just refuses to lie down. The Swiss ace has a chance to tee up set point on his own serve but powers a forehand wide. It allows Nadal another bite at it and he holds his serves before securing the match when Wawrinka fires into the net.

NADAL 7-6 6-6 - TIE BREAK! A second tie break looms as Wawrinka continues to mix brilliance with unforced errors. A woeful volley at the net and a double fault offer Nadal a sniff of a chance at 30-30. But an epic rally of 28 shots then sees the Spaniard slice long before the Swiss hammers down an ace to level it up.

NADAL 7-6 6-5 - Nadal holds serve but Wawrinka made him work for it. The Spaniard looked in complete control as he surged 40-0 up. But two moments of genius from the world number eight got him back in contention before Nadal made sure of the game with a fine serve. Quite possibly Rafa's best service game of the match despite dropping two points.

NADAL 7-6 5-5 - Superb play from Stan the Man. Nadal gets ahead to heap pressure on his serve but Wawrinka responds by taking the next four points, flashing a stunning winner down the line to seal the game.

NADAL 7-6 5-4 - This has been such a closely-fought contest with both players mixing the sublime with the not-so-sublime. At 30-15 Rafa miscues a forehand so badly, it's quite possibly a contender for the worst shot he has hit all year. Not to be outdone, Wawrinka fires long after dominating the following rally before netting a routine forehand to give the Spanish star the edge.

NADAL 7-6 4-4 - We're all-square in this second set. A purple patch has seen Wawrinka take 11 of the last 14 points. A great recovery from the Swiss who had looked dead and buried at 4-1.

NADAL 7-6 4-3 - BREAK! Finally, Wawrinka gets some reward for his adventurous approach on the Nadal serve. At 15-40 he dominates from the baseline before snaring the break by coming forward and dispatching a volley at the net via the cord.

NADAL 7-6 4-2 - With the match disappearing on his horizon, Wawrinka is able to play freely and easily serves out to love. It's shame he hasn't been able to play like that in the moments of real pressure.

NADAL 7-6 4-1 - Wawrinka just can't make his opportunities count. At 30-30 Nadal's attempted winner is called out, despite replays showing otherwise. It allows the Swiss the chance to break but he tightens up again and fires a forehand too long. As has been the pattern throughout, Rafa doesn't need asking twice and wins the next two points to consolidate his initial break.

NADAL 7-6 3-1 - BREAK! You get the feeling Wawrinka is battling himself just as much as Nadal here. He keeps getting into good situations but somehow fails to convert. Maybe it's a mental thing given his poor record against the world number one. A shocking first point blunder puts him on the backfoot and Nadal racks up three break points. A wayward forehand gifts Nadal the game on his second. It's a long way back now.

NADAL 7-6 2-1 - A superb start to the game goes south for Wawrinka. The world number eight shows great athleticism to reach a Nadal volley at the net and tee up two break points. But the old demons return to haunt him as he gets over-eager with two attempted winners and hands Rafa the reprieve. The Spain ace seizes the opportunity and sees it out to hold serve. Psychologically that wasn't great for Stan.

NADAL 7-6 1-1 - Wawrinka uses his anger to good effect, romping through his service game to love.

NADAL 7-6 1-0 - A game rife with surprising errors eventually goes the way of Nadal. The Spaniard looked like making short work of a forlorn Wawrinka but a woeful volley at 30-15 gave the Swiss hope. Another Nadal forehand long takes the game to deuce before the world number one eventually comes through. Both players getting a bit agitated out there with Stan the man commenting that Rafa was taking too long between points.

NADAL 7-6 (7-5) SET! So, so close for Wawrinka. At 5-5 on the Nadal serve he appears to have the Spaniard. But a magnificent defensive shot stuns the Swiss number two and he fires his next forehand long. Nadal then takes advantage of Stan's trip near the net to fire a winner into the empty court to break and claim the set.

NADAL 6-6 - TIE BREAK! Nadal drops the first point on his serve but finally ends his mini slump with some robust play. Wawrinka flaps at an attempted backhand down the line and Rafa sees it out to 15. Tie break time.

NADAL 5-6 - Wawrinka is on fire at just the right moment. Some big serving puts him in control and he claims the game to love with a backhand volley across court at the net. The pressure is right back on Nadal. Seven points in a row for the Swiss number two.

NADAL 5-5 - BREAK! A surprise twist! Wawrinka's biggest weapon is that backhand and he produces when it matters most to restore parity in this first set. Nadal has no answer to Stan the man's determination and he forces the break with a thumping forehand.

NADAL 5-4 - Relatively routine for Wawrinka who finds form with his serve just in time to see out the game to 15. Rafa to serve for the first set.

NADAL 5-3 - A big wobble for Nadal as Stan dominates the rallies with some clever tactical approach play. The Swiss star grabs a break point with a thunderous backhand winner but then miscues to give Rafa a reprieve. More magic from the underdog sees him snare another break point with a belter down the line but again he can't convert. Nadal digs deep and benefits from some unforced errors from his opponent to finally see out the game.