LONDON — Novak Djokovic made his way back into the championship match at the ATP Finals, beating Juan Martin del Potro 4-6, 6-3, 6-2 Sunday. The 2008 champion was broken early in the second set, but he broke right back to 2-2 and then took Del Potro's serve again to take a 5-3 lead. In the third, Djokovic decided things by winning 12 of 13 points in a three-game stretch to take a 3-1 lead. He broke again three games later. In the other semifinal match at the O2 Arena, six-time champion Roger Federer will face Andy Murray. Federer beat Murray in the Wimbledon final to win his seventh title at the All England Club, but Murray bounced back to beat Federer in the Olympic final on the same Center Court grass. The semifinals lineup was settled following David Ferrer's 4-6, 6-3, 6-1 win over Janko Tipsarevic Saturday. Both Ferrer and Tipsarevic were already eliminated from the season-ending event after del Potro's surprise victory against Federer earlier Saturday, but the result of their match was still significant as, due to the convoluted rules of the tournament, it would affect the semifinal match-ups. In the end, Ferrer's second win of the competition meant Federer topped Group B and would play Murray, while del Potro finished second and went up against Djokovic. Indian duo win grudge match Mahesh Bhupathi and Rohan Bopanna won their grudge match with India's Leander Paes and his Czech partner Radek Stepanek as the Indian pair reached the final of the ATP Tour Finals with a 4-6, 6-1, 12-10 victory at London's O2 Arena also Sunday. The semifinal showdown always promised to be a bitter battle after Bhupathi refused to be partnered with Paes at the London Olympics earlier this year, causing an ugly rift that caused several months of chaos in Indian tennis. Bhupathi and Paes had a successful doubles partnership for several years, but split up when their relationship deteriorated. Paes and Stepanek defeated Bhupathi and Bopanna in the final of the Shanghai Masters earlier this year in the rivals' first meeting since the Olympics, so this was an especially sweet moment of revenge for the Indian pair. In Monday's final, they will play the winners of the other semifinal between Spanish duo Marcel Granollers and Marc Lopez and Wimbledon doubles champions Jonathan Marray and and Frederik Nielsen. — Agencies