Kazakhstan's top men's singles player Alexander Bublik started his campaign at the ATP 250 clay-court tournament in Gstaad, Switzerland, with a loss, according to infohub.kz.
The world No. 11, who was the top seed and received a bye into the second round, faced France's Quentin Halys, ranked 90th.
The match began on July 16 but was interrupted several times by rain, with the players finishing it the next day.
The contest lasted the full three sets, two of which went to tiebreaks. Halys won 6:7 (4:7), 6:4, 7:6 (7:5).
The players spent 2 hours 22 minutes on court, during which Bublik hit 13 aces, committed six double faults, and failed to convert both break points.
The Kazakh could not defend his title in Gstaad and will lose 200 ranking points.
Halys will face another Kazakh, Alexander Shevchenko, in the quarterfinals of the Swiss clay-court event.