Ugo Humbert shocked fourth seed Andrey Rublev 6-3, 7-6(4) on Sunday to claim the Halle grass title, third of his career.
The 31st-ranked Frenchman added the German trophy to Auckland and Antwerp in 2020.
Rublev was chasing his fifth career title at the elite 500 level but was unable to overcome an inspired opponent.
Humbert claimed a narrow victory with nine aces and one break of serve; he is the second French trophy holder after Henri Leconte, who won the inaugural Halle edition in 1993.
“It is incredible. It is the best victory of my career,” Humbert said. “I am very proud because it wasn’t easy.
“I was a little bit tired, but I tried to stay focused on each point, and did what I could, so it is very nice. Physically, it was tough, and I tried to take my chances when I could, and I won.”
Victory took 87 minutes with Rublev still doing well this season with a solid 33-10 record and two titles.
“It was a really great week for me, with my first grass final,” the russian said.
“It was not easy in the beginning, everything was so fast, just one or two shots.
“The second set was good for both of us. In the tie-break I had a big chance with the forehand but I missed them, but it happens and I can’t control it. He was serving very well.”
Main photo:- Ugo Humbert wins in Halle ©ATPTour.com