Three-time defending champion Novak Djokovic reaches Dubai semifinals . He beat fellow Serb Janko Tipsarevic to revenge ATP World Tour Finals defeat . We both got a little bit nervous towards the end , I guess , and it was just luck to prevail . '' Djokovic's win means he has won all four of his matches in the tournament so far this year and is now just one match away from a record eighth title at the event -- which will be Four-time champion Roger Federer also through to last four .
Three-time defending champion Novak Djokovic reaches Dubai semifinals . He beat fellow Serb Janko Tipsarevic to revenge ATP World Tour Finals defeat . Djokovic's win means he has won all four of his matches in the tournament so far this year and is now just one match away from a record eighth title at the event -- which will be Four-time champion Roger Federer also through to last four .