Results from the ATP tournament in Belgrade on Friday (x denotes seeding): Quarter-finals Novak Djokovic (SRB x1) bt Miomir Kecmanovic (SRB x8) 6-1, 6-3 Aslan Karatsev (RUS x3) bt Gianluca Mager (ITA) 6-3, 6-4 Taro Daniel (JPN) bt Federico Delbonis (ARG) 4-6, 6-1, 7-5 Matteo Berrettini (ITA x2) bt Filip Krajinovic (SRB x5) 6-4, 6-4 afp