Liam Broady's excellent run at the St Petersburg Open came to an end with a 6-3 2-6 6-4 quarter-final defeat by Bosnia and Herzegovina's Damir Dzumhur.
The world number 242, ranked 187 places below his opponent, broke twice in the second set to level the match.
Broady, 23, had an early break in the decider but Dzumhur fought back and then saved three break points in the ninth game.
Dzumhur then broke the British number seven in the 10th game to seal victory.
Broady went through two rounds of qualifying before he defeated Latvian Ernests Gulbis in round one.