Belbek stayed on stoutly under a well-timed ride from Mickael Barzalona to narrowly take the Qatar Prix Jean-Luc Lagardere at ParisLongchamp.
The Andre Fabre-trained colt was always near the front rank in the seven-furlong Group One contest and sat just off the pace, set by Vicious Harry.
Barzalona, winning the race for a fourth time, made his move aboard Belbek inside the final furlong and out-stayed Gamestop, who had hit the front 200 yards from the winning post.
Breizh Sky finished off well in third, with the Johnny Murtagh-trained Shartash failing to pick up sufficiently in the ground, finishing fourth.
“He failed to settle in his first race but he is a good-looking, well-bred horse.” said Fabre.
“Let’s see how he is, but I might take him to the Vertem Futurity Trophy at Doncaster. If he ran again it could be there.
“The Breeders’ Cup (for which he qualified by winning) would not be my favoured option.”
Paddy Power have introduced Belbek as a 12-1 chance for the Doncaster Group One on October 22.
Owner Nurlan Bizakov suggested plans would be left in the hands of Fabre.
“It’s up to Andre. If he is bouncing and fresh, we will see. Whatever Andre suggests as he is the greatest trainer,” he said.