Federer pulls out of ATP Final, Djokovic wins

Novak Djokovic had sealed his third ATP Tour World Championship in a row before the game had started after Roger Federer pulled out of competing in the final at the O2 Arena in London.

The 33-year-old withdrew from the final just 30 minutes before the start, having picked up back problems in his grueling three-set semi-final win over Swiss compatriot and Australian Open champion Stanislav Wawrinka, which lasted over three hours.

"Unfortunately I'm not match fit to play match tonight," Federer told a naturally disappointed crowd.

"Clearly I wish it wasn't this way. You try all year to be ready for the ATP World Tour Finals and I didn't want to end this way.

"I tried everything I could last night and today -- painkillers, rest -- until the very end, but I can't compete at this level with Novak. In a final like this and at my age, it would be too risky. I hope you understand."

Federer has been plagued by back problems since 2013, but the 17-time Grand Slam champion will now focus on recovering ahead of his Davis Cup encounter on Friday in France.

"I hurt my back late in the match yesterday against Stan. I am very disappointed and I hope to be feeling better soon," Federer said.

"It's been an extremely difficult decision because I love playing in London and the ATP World Tour Finals have been an absolute highlight of my career."

Djokovic's third consecutive title in London means he'll end the year as the world number one in the ATP Rankings.

The Serb lined up to face Andy Murray in a hastily-arranged friendly match to appease the paying supporters, some of whom paid around $600 for a ticket.

The 25-year-old rounds off a fantastic season, ending 2014 as Wimbledon champion, US Open semi-finalist and French Open finalist.

It has got even better in the last few months for Djokovic who celebrated the birth of his son in October.

rd / (AFP, AP)