Three -time defending champion Roger Federer reaches Dubai semifinals . He beat fellow Australian to revenge the ATP World Tour Finals defeat . Djokovic to face Novak Djokovic in repeat of their Serb Janko Tipsarevic Open epic . 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 to face Andy Murray in repeat of their Australian Open epic . Four-time champion Roger Federer also through to last four .