Djokovic gets to solid start in ATP World Tour Finals with victory over Federer

World number two Novak Djokovic has kept alive his hopes of ending the year as number one by beating Swiss ace Roger Federer in their riveting Group B clash at the Barclays ATP World Tour Finals.

Djokovic followed up Saturday's Paris semi-final victory with a 6-4 6-7 (2-7) 6-2 win at the O2 Arena, although he will lose his number one spot to world number two Rafael Nadal if the Spaniard beats Swiss Stanislas Wawrinka on Wednesday.

According to the BBC, with 23 Grand Slam and eight ATP Finals titles between them, Djokovic and Federer provided the first real heavyweight clash of the week in London, and there was hardly a spare seat to be found among more than 17,000 spectators.

Djokovic admitted that it was a big challenge playing against Federer, adding that he is going to take his day off to 'recharge his batteries' for his next match against Argentine Juan Martin del Potro.

The report mentioned that Federer remains a huge draw despite slipping to seventh in the rankings this year, something the Swiss has put down largely to a back injury he has now recovered from, the report added.