Novak Djokovic Against Roger Federer In Semi-finals Clash At The US Open

World number one Novak Djokovic had been leading 7-6 6-7 6-0 3-0 when his Serbian Davis Cup team mate Janko Tipsarevic, retired with a leg injury after three hours, 27 minutes of play at Arthur Ashe Stadium after feeling sharp pain in his left leg.

Read moreNovak Djokovic Against Roger Federer In Semi-finals Clash At The US Open