Jacob Fearnley's run at Queen's came to an end when the British number two was beaten by Jiri Lehecka 7-5 6-2 in the quarter-finals.
The 23-year-old was playing in his first last-eight match of an ATP Tour event after producing a brilliant display against French qualifier Corentin Moutet on Thursday.
But Czech world number 30 Lehecka proved too much for him on another hot day in west London.
Things had looked promising for Fearnley after he got the first break of the match, but the world number 60 gave it up immediately following three double faults.
More mistakes on serve proved costly again as Lehecka got the double break to lead 6-5 before serving out the set.
Lehecka then continued the momentum in the second set, getting another double break to go on and seal the win and his place in the semi-finals, where he will play the winner of Friday's match between British number one Jack Draper and American Brandon Nakashima.