British number three Cameron Norrie failed to take a match point as he lost in the first round of the Astana Open in Kazakhstan.
The 25-year-old world number 70, lost 5-7 7-6 (8-6) 6-2 to Australian Jordan Thompson, ranked 10 places higher.
Left-hander Norrie, yet to win an ATP Tour title, reached the last eight in St Petersburg this month.
But on Monday, eighth seed Thompson broke twice in the deciding set to win in two hours 40 minutes.