Ryan Moore's objection was overruled after hot favourite Scandinavia was beaten by Caballo De Mar in a tight finish to the Qatar Prix du Cadran at Paris Longchamp.
A stewards' enquiry looked into interference between the two horses on the run to the line, but the result was upheld, giving George Scott and owners Victorious Forever a big Arc weekend double after the Prix Dollar success of Wimbledon Hawkeye.
Contact in the closing stages
Caballo De Mar, ridden by Oisin Murphy, loomed up to Scandinavia and they battled it out for the prize after 2m 4f. Late drama ensued when the winner leaned into his rival and made contact, which led to Moore's protest.
"The stewards inquired into an incident 50 metres from the finish line after an objection was lodged by Ryan Moore," said stewards' secretary Samuel Fargeat via the Racing Post.
"After hearing from both jockeys and reviewing the film, the stewards were not satisfied that the horse suffering interference would have finished in front without that interference."
Favourite's long season
Scandinavia was sent off the 1-6 favourite after racking up eight victories on the trot, including the Gold Cup at Royal Ascot.
"He ran a great race and it's been a long season for him," said Aidan O'Brien. "The ground was a little bit on the slower side for him. Ryan said he was coming back at him (the winner)."
Murphy told Sky Sports Racing that he was surprised there was a stewards enquiry. "I felt him shift inwards and corrected him," he said. "I'm obviously delighted that the stewards decided Caballo De Mar deserved to win."
Return to form
The five-year-old had returned to form in recent weeks after trailing home 61 lengths behind Scandinavia in the Ascot Gold Cup, with the vet reporting afterwards that Scott's star was showing signs of heat stress.
"It was an amazing performance and it's so special to beat Scandinavia after being beaten two furlongs by him at Ascot," Scott said. "He's a credit to everyone at home and the hard work that has gone into him. These moments are what we do it for and what we live for. Oisin gave him a great ride."