Portuguese Nuno Borges, the No 6 seed, won against Greek wildcard Stefanos Sakellaridis 7-6 (4), 6-3 to reach the second round of the Belgrade Open at the Belgrade Arena on Sunday evening.
Borges, ranked No 46, will play the winner of the match between American qualifier Eliot Spizzirri and Serb Laslo Djere next.
Belgrade ATP 250, other first-round results (Belgrade Arena, hard, EUR 766.715, most recent results first):
Mackenzie McDonald vs. Tomas Martin Etcheverry
Yannick Hanfmann vs. Ivan Ivanov
Marcos Giron vs. Pedro Martinez Portero
Alexandre Muller vs. Jan-Lennard Struff
Reilly Opelka vs. Vit Kopriva
Stan Wawrinka vs. Botic van de Zandschulp
Miomir Kecmanovic vs. Kamil Majchrzak
Eliot Spizzirri vs. Laslo Djere
Damir Dzumhur vs. Jacob Fearnley
Alexei Popyrin vs. Sebastian Korda
Alejandro Tabilo vs. Adam Walton: sunday