BELGRADE — World No 1 tennis player Novak Djokovic of Serbia reached the semifinals of the Serbia Open in Belgrade on Thursday by beating his compatriot Miomir Kecmanovic 4-6, 6-3, 6-3.,Djokovic allowed Kecmanovic easy breaks in the first set, but managed to regain momentum in the next two sets and turned the match around.,In Saturday’s semifinal match, Djokovic will face Russia’s Karen Khachanov, who beat Thiago Monteiro of Brazil 7-5, 6-4.,Serbia Open takes place at the Novak Tennis Centre in Belgrade from April 17 to 24.