- World No.1 and World No.2 will play in Monday's final at London's O2 Arena
- Nadal beat Roger Federer 7-5 6-3 while Djokovic beat Stanislas Wawrinka 6-3 6-3
- Pair have met three times on hardcourts this season with Nadal winning twice
- Djokovic triumphed in most recent encounter in China and is unbeaten in 21 matches
Defending champion Novak Djokovic will play Rafael Nadal in the final of the ATP World Tour Finals at London's O2 Arena after both men comfortably overcame their Swiss opponents in Sunday's semifinals.
World No.1 Nadal dispatched his old adversary Roger Federer in straight sets 7-5 6-3 to book only his second appearance in the season-ending tournament final while Djokovic dismissed Stanislas Wawrinka 6-3 6-3.
The results set up what should be an absorbing match on Monday evening and a fitting finale to a season the Serb and the Spaniard have dominated. Together, the pair have amassed more than $20 million in prize money in 2013 and won 16 titles -- Nadal has ten to Djokovic's six.
They have met three times on hardcourts this year with Nadal shading it 2-1 thanks to wins in Montreal in August and the following month at Flushing Meadows. But Djokovic won their most recent encounter at the China Open in straight sets and is unbeaten in 21 matches since losing to the Spaniard at the U.S. Open.
"It's going to be a great final. I hope all the crowd will enjoy it because we definitely do on the court. It's always a thrilling competition between me and Rafa. It's the biggest match of this part of the year for both of us and we want to end up with the title. The better (man) will win," Djokovic said.
Nadal is also looking forward to the challenge.
"It's the perfect way to finish the season, probably one of the best seasons of my career," Nadal said after his victory over Federer.
"This is a special tournament but I have lost here before and not had the most luck, so it's great to be in the final."
Nadal overcame Federer in 79 minutes shading a hard-fought first set before easing through the second as Federer was let down by some untidy errors.
A loose forehand gifted Nadal a break of serve before a wayward volley handed Nadal a 75th win of the season in a remarkable comeback year.
"I just struggled to stay consistent enough throughout the match and that's why he deserved to win. He was better today," Federer said afterwards.
Djokovic, meanwhile, coasted to victory over Wawrinka who was competing in his first ATP World Tour Finals.
The 28-year-old Swiss broke the Serb in the third game, before Djokovic assumed total control.
The world No.2 broke back in the next game and again in the eighth before serving out the set.
Wawrinka then lost his opening service game in the second as Djokovic once again quietly dominated with a trademark blend of defense and attack.
"It was a very enjoyable match for me today. The performance was by far the best so far in the tournament," Djokovic said.