Sarafina became a warmer favourite for next month's Prix de l'Arc de Triomphe at Longchamp after a dramatic Group Two Qatar Prix Foy win at the Paris track.
The filly, a luckless third in last year's Arc, accelerated from the last place in the four-runner field.
Jockey Christophe Lemaire pushed her through the narrowest of gaps.
The head-on camera indicated runner-up Hiruno D'Amour and St Nicholas Abbey, who was third, suffered interference but the result stood after an inquiry.
It took 15 minutes before the stewards allowed the winner, running in the silks of owner the Aga Khan, and trained, like Group Two Prix Niel winner Reliable Man, by Alain de Royer-Dupre to retain the £64,000 first prize.
Despite the controversy, this looked a perfect Arc warm-up race for Sarafina whose unfaltering bravery when asked to go through the gap by Lemaire particularly impressed.
With Reliable Man comfortably turning the tables on Meandre (they had been third and first respectively in the Grand Prix de Paris in July), de Royer-Dupre approaches the Prix de l'Arc de Triomphe on 2 October with a very strong hand indeed.
And, on an informative day ahead of next month's Longchamp highlight, Galikova, a half sister to the brilliant Goldikova, booked a place in the big race line-up with a smooth success, upped in distance to a mile and a half, in the Group One Qatar Prix Vermeille.