Stan Wawrinka missed out on the final of the Sofia Open as he suffered a stunning loss to Mirza Basic.
The three-time grand slam champion was beaten 7-6 (8-6) 6-4 by Basic - ranked 129th in the world - the Bosnian earning a place in his first ATP final.
He will now take on Marius Copil, who defeated Jozef Kovalik 6-4 6-2.
"I think I played a very, very good match. I was serving very good, so I think this helped me a lot," Basic said after his first win over a top-20 player. "It's a big success for me. My first final after I played a semi-final last year.
"Also it's a big achievement because it will be the first time, after this week, I'm going to be top 100 [in the ATP rankings] so it's an even bigger success."
It will be an all-French affair at the Open Sud de France, with Richard Gasquet reaching his sixth consecutive final at the tournament.
Gasquet came through a three-set battle with David Goffin 6-4 0-6 6-3, setting up a showdown with Lucas Pouille, who benefited from a huge stroke of fortune in his match with Jo-Wilfried Tsonga.
Tsonga was leading 6-1 5-5 when a left hamstring injury forced him to retire, meaning it is Pouille who stands between Gasquet and a fourth title in six years.