LONDON, ENGLAND - NOVEMBER 11: Novak Djokovic of Serbia serves during his men's singles semifinal match against Juan Martin Del Potro of Argentina during day seven of the ATP World Tour Finals at O2 Arena on November 11, 2012 in London, England. (Photo by Michael Regan/Getty Images)

London – Novak Djokovic cut giant Argentine Juan Martin del Potro down to size as the world number one battled into the final of the ATP Tour Finals with a 4-6, 6-3, 6-2 victory on Sunday.

Djokovic will play defending champion Roger Federer or third seed Andy Murray in Monday's final after coming from a set and a break down to topple the 6ft 6in former US Open champion in a gruelling semifinal clash lasting two hours and 11 minutes at London's O2 Arena. – AFP