Although unbeaten in two previous starts, Jean-Claude Rouget’s Valyra was allowed to start at 25-1 as seemingly the least fancied of three runners for the Aga Khan.
The previously unbeaten Beauty Parlour was sent off the 5-6 favourite and looked likely to collect for odds-on backers when cruising to the front at the top of the home straight under Christophe Soumillon.
But while she beat the rest of her opponents comfortably, she could never shake off Valyra, who eventually wore down the market leader to claim the Group One prize, earning a 14-1 quote from Paddy Power for the Prix de l’Arc de Triomphe.
Aidan O’Brien’s Kissed cut out the early running under the trainer’s son, Joseph, but dropped away tamely in the straight and was virtually pulled up, beating only one home.
Stablemate Up fared a little better under Ryan Moore, but was still well beaten into seventh place having been at the rear of the field through the early stages.
Murtagh, who is retained for the Aga Khan’s horses in Ireland, said: “I was asked last Monday to come and ride her. I liked her straight away, but obviously didn’t know if she was a Group One filly.
“During the race, she was very relaxed and I think that is her strength. She followed them through very easily and two and half out I knew we were going to get there, she picked up beautifully. She really quickened.”
Asked if she would stay further, he said: “I think she will stay and it might just turn out that a mile and a half will be her best trip. She could be even better than she is now.”
Rouget said: “We decided to supplement her after she won her race at Bordeaux.
“I was really impressed, as everyone had been talking about Beauty Parlour as the next Zarkava. So the fact that she beat her, and also the way she beat her, was obviously extremely pleasing.
“I think these are really good fillies.
“I don’t think she is entered in the Prix de l’Arc de Triomphe. We shall see, but obviously everything is open to her.”
When asked if he would consider supplementing the filly for the Arc, the Aga Khan did not hesitate and simply said: “yes”.
Kissed was found to have suffered an injury, and was retired after the race.
O’Brien’s wife Anne-Marie tweeted: “Kissed sustained a fracture of the sesamoid bones of her left fore at Chantilly today. She is comfortable and will now be retired to stud.”