Nadal and Djokovic in final as Swiss melt away

Rafael Nadal of Spain returns the ball during his men's singles tennis match against Roger Federer of Switzerland at the ATP World Tour Finals at the O2 Arena in London, Nov 10, 2013. [Photo/Agencies]

Novak Djokovic of Serbia hits a return to Stanislas Wawrinka of Switzerland during their men's semifinal singles tennis match at the ATP World Tour Finals at the O2 Arena in London, Nov 10, 2013. [Photo/Agencies]

LONDON - Switzerland's challenge at the ATP World Tour Finals melted away like an Alpine glacier in a heatwave on Sunday as Rafa Nadal and Novak Djokovic marched on to the grand finale.

Nadal muscled past Roger Federer 7-5 6-3 before Djokovic extended his hot streak to 21 consecutive victories with a routine 6-3 6-3 defeat of Stanislas Wawrinka.

Fittingly the regular season will end with a $1.92 million shoot-out between the two dominant forces in men's tennis who will go head-to-head for the 39th time.

Djokovic, who like Nadal had a 100 percent record in round robin play, will be desperate to retain his title after ceding the world number one ranking to the relentless Spaniard in October.

"We are both having a great season this year. This is probably the best possible final we have here in London. We'll see what happens tomorrow," Djokovic, who was rock solid against tournament debutant Wawrinka, told a news conference.

"This is probably the most competitive tournament that we have after grand slams in our sport, and we both want to end this season in the best possible way and end it with a title."

Predicting a winner will be a tough task.

Australian Open champion Djokovic is unbeaten since losing the US Open final to Nadal in September while Nadal, whose 10 titles this year include the French Open, hopes to cap an astonishing comeback following a seven-month injury lay-off.

"The most important thing for me is that on the toughest surface for me, the most difficult one, I was able to win four matches against top-eight players," Nadal, whose bulging CV is only missing a Tour Finals title, told reporters.

"Now there remains one more match, probably the hardest, and I need to play my best match to have a chance tomorrow."

Nadal boasted a 21-10 career record over Federer but Sunday's victory was his first on the kind of indoor court that has proved problematic to the 27-year-old during his career.

Former world number one Federer began in positive fashion, hardly dropping a point in his opening three service games and having a golden chance to break Nadal in the sixth game, only to send a wild forehand whistling over the baseline.

"I went for it when I had a chance for a breakpoint in the first set. Maybe I shouldn't have, but I did. No regrets there, I guess," Federer, who has ended the year with a solitary title, his worst haul since 2001, told reporters.

"I just struggled to stay consistent enough throughout the match, and that's why he deserved to win. He was better today."

Federer offered hope to his fans when Nadal served for the opening set, winning a scintillating baseline exchange at 15-30 with a sweetly-timed forehand winner and scoring a break when his opponent ballooned a forehand out.