Andy Murray is out of the Moselle Open after the former world number one was beaten by top seed Hubert Hurkacz.
Poland's world number 13 Hurkacz, 24, won 7-6 (7-4) 6-3 and will face German qualifier Peter Gojowczyk for a place in the final in Metz, France.
Hurkacz survived three break points to hold for 4-4 in a close opening set, which he clinched in a tie-break.
The 2021 Wimbledon semi-finalist closed out the match after breaking Murray's serve for a 3-1 lead in the second set.
Britain's Murray, a wildcard at the event and currently 113th in the rankings, had beaten the world number 26 Ugo Humbert and Vasek Pospisil, ranked 66th, to reach the last eight.
The three-time Grand Slam champion, who reached the Moselle final in 2007, maintained the pressure on Hurkacz until the end and survived two match points to set up a break-back opportunity - but the Pole held his nerve.
The Scot, 34, lost in the first round of the US Open to world number three Stefanos Tsitsipas in August and fell in last 16 at the Rennes Open last week.
"I'm not that interested in playing well and losing. I want to be winning these matches. But the consistency this week was better than it was over in the States," Murray said.
"My goal's not to get in the top 100. I would want to get back in the top 10, [that] would be more something that would motivate me in terms of a goal. Winning tournaments and getting up towards the top of the rankings is motivating to me.
"Hopefully between now and the end of the year I can play a lot of matches and try to do better than this week."
Hurkacz's next opponent, world number 101 Gojowczyk, came from a set down to defeat American Marcos Giron 3-6 6-1 6-3.