Rafael Nadal booked his place in the final of the ATP World Tour Finals after seeing off his old foe Roger Federer in straight sets.

The year-end world No. 1 is looking to win the season-finale for the first time in his career, and will face either Novak Djokovic or Stanislas Wawrinka in what will only be his second appearance in the final on Monday night after a 7-5 6-3 victory.

The Verdict

  • So Roger Federer's season comes to an end, but the Swiss can be pleased with how he has played at the O2 in his four matches.

  • He was down and out against Juan Martin del Potro yesterday, but showed the fighting spirit missing from his game in 2013 to hit back, and perhaps the efforts of such a hard-fought win took their toll on the record champion.

  • Rafael Nadal, with the extra day off, continues to get better as the tournament goes on, and even if the Spaniard is not a fan of the indoor arenas, will now have a shot at lifting the title for the first time.

  • He should have Del Potro to thank for forcing Federer to dig deep, and after he took the first set and secured the break, knew he had Federer exactly where he wanted him, making his opponent take unwanted risks in pressure situations to make it through to the final.

Heading into the encounter Nadal had won 21 out of 31 matches against Federer, but the latter had recorded four wins from four in indoor ties.

And that statistic may have played on Nadal's mind when Federer was looking to pounce midway through the opening set. Nadal stood firm to take his opportunity, and after securing the break early on in the second set was able to close out the win to collect his fourth victory in 2013 over the Swiss.

Both players received standing ovations from the crowd as the atmosphere generated felt like it was a final.

Unlike against Juan Martin del Potro when he lost his opening service game, Federer made a great start, serving an ace, finishing a volley at the net and striking a forehand winner to take the opening game.

Nadal went one better and did not drop a point on his service opener, and the Spaniard put pressure on Federer in the following game after coming from 40-0 to deuce. However, an ace and another winner off the forehand saved the Swiss to see him take a 2-1 lead.

Nadal yet again raced through his service game, still yet to concede a point, but at 3-2 behind, the year-end world No. 1 faced problems as Federer was intent on claiming the break.

But on three occasions he failed to convert any of them in the sixth game as Nadal clinically saved the points. Two easy holds arrived in the next two games, but it was Nadal who punished Federer to break for 5-4 with a ferocious forehand which flashed past his stranded opponent.

A rally which had the O2 crowd on their feet resulted in Federer setting up break-back points, and Nadal failed to close out the first set as Federer fought back to 5-5.

However, a few errors crept into Federer's game after all the hard work to get himself back in the set, and Nadal capitalised to take a 6-5 lead, before holding to love to wrap up the opening set.

The pair shared the first four games of the second set, but when Federer hit the net in the fifth game, he handed the break to Nadal, and the Spaniard could now see the finishing line in building a 4-2 advantage.

Nadal went one game from the win at 5-3, and on his first match point sealed the win when Federer's volley at the net went long.

On the loss, Federer said: "I struggled to stay consistent throughout the match, and that's why he deserved to win, he was better today. It's unbelievable that he gets away with playing so far back indoors these days, but credit to him for making that work."