Benoit Paire hit back from a set and a break down to score his first career win over compatriot Jo-Wilfried Tsonga and reach the final of the Grand Prix Hassan II in Marrakech.
Former world number five Tsonga showed signs of returning to top form as he breezed through the first set and established a 3-1 lead in the second.
But Paire then capitalised on his opponent's increasingly erratic play to win three games in a row and change the course of the match, eventually coming through 2-6 6-4 6-3.
Paire told atptour.com: "He played well in the beginning and I was struggling with the sun. I'm very happy that I won because it is the first time I've beaten him."
In the final Paire will face three-time champion Pablo Andujar of Spain, who had no such problems dismissing fourth seed Gilles Simon 6-1 6-1 in just 74 minutes.