Novak Djokovic won the latest installment of his thrilling rivalry with Andy Murray as the world number one fought back to secure a dramatic 4-6, 6-3, 7-5 victory in the ATP Tour Finals atLondon’s O2 Arena on Wednesday. Djokovic has a 100 percent record after two Group A matches at the season-ending event and will be guaranteed a place in the semi-finals if France’s Jo-Wilfried Tsonga defeats Czech fifth seed Tomas Berdych later on Wednesday. World number three Murray now needs to win his final group match against Tsonga on Friday to avoid an early exit. Ferrer wins Spain’s David Ferrer extending his winning run to 11 matches with a hard-fought 6-3, 3-6, 6-4 victory over Juan Martin del Potro at the ATP Tour Finals on Tuesday. Ferrer had to dig deep to maintain that fine form, but he was able to do just that as he subdued del Potro in two hours and 16 minutes.