World number one Daniil Medvedev, playing his first match in six weeks, beat Australian qualifier Rinky Hijikata 6-4, 6-3 on Wednesday at the ATP hard court tournament in Los Cabos, Mexico.
It was a milestone 250th match win of the reigning US Open champion's career.
"Someone told me this a few days ago," Medvedev said after the match. "Otherwise I would not have known. That's nice, a milestone in a way.
"I want more victories, but that's nice to have 250. We'll try to get more."
Medvedev is playing his first tournament since bowing out of the quarter-finals at Mallorca on June 23. He missed Wimbledon because of its ban of Russian and Belarussian players in the wake of Russia's invasion of Ukraine.
Medvedev next faces Ricardas Berankis of Lithuania, who beat Argentina's Facundo Bagnis 7-6 (7/4), 6-3.
Second-seeded Canadian Felix Auger-Aliassime also advanced, beating Mexico's Alex Hernandez 6-3, 7-5.