British number one Dan Evans saw four match points slip by as he lost 6-4 6-7 (7-9) 6-4 to Ugo Humbert of France in the European Open semi-finals.
It was the third three-set match of the week for world number 35 Evans, seeking his first ATP Tour title.
In his first meeting with left-hander Humbert, ranked 38, Evans was beaten in three hours 12 minutes.
Humbert, 22, faces either fourth seed Grigor Dimitrov or Australian Alex de Minaur in Sunday's final.
The Frenchman, who claimed his maiden ATP title in Auckland in January, trailed 6-3 in the second set tie-break to 30-year-old Evans - but whittled that advantage away.