Results from the first day of the ATP event at Belgrade, on Sunday (x denotes seed): 1st rd Federico Coria (ARG) bt Marko Topo (SRB) 4-6, 6-2, 6-0 Jeremy Chardy (FRA) bt Tennys Sandgren (USA) 6-4, 6-2 Pedja Krstin (SRB) bt Soonwoo Kwon (KOR) 6-2, 3-6, 6-1 afp