Luca Van Assche, ranked 87th in the world, toppled Switzerland's Stan Wawrinka (84th) in three sets 1-6, 7-6 (7/4), 6-4 on Monday. The 18-year-old will play his second-round match against world No.

1 Novak Djokovic of Serbia, who is exempt from the first round. This ATP 250 tournament is traditionally held in Belgrade. It was relocated this season to Banja Luka, Bosnia and Herzegovina.