Diamond Necklace tasted defeat for the first time as Aventure served a reminder of her top-class credentials in the Sumbe Prix Jean et Louis Romanet at Deauville on Sunday.

Aidan O’Brien’s daughter of St Mark’s Basilica was expected to dazzle once again in France, as she has done when landing the Prix Marcel Boussac, Poule d’Essai Des Pouliches and Prix de Diane on her travels during what was an unbeaten six-race career to date.

However, she had no answer to the experience of her Christophe Ferland-trained elder, who added to last year’s Group 1 strike in the Prix Vermeille.

In a close-up third was the Charlie Johnston-trained Timeforshowcasing, who was a big race in the hands of Jack Mitchell.

Pierre-Yves Bureau, racing manager for owners the Wertheimer brothers, said: “We’re very happy and when she won the Prix Corrida earlier this year we were very happy but then made a mistake by running over a mile and a half in the Grand Prix de Saint-Cloud.

“There was a strong field of fillies including Diamond Necklace, but what our mare did is just wonderful, she is such a champion. We will be very happy to have her as a broodmare one day, but we will enjoy her racing for the moment!”

However, there will be no third attempt at Europe’s richest middle-distance prize for the five-year-old who will instead remain at 10 furlongs for the Prix de l’Opera post the main event on Arc day before a possible trip to Keeneland.

Bureau added: “It’s quite unusual, but this filly is getting more speed with age and 10 furlongs is her perfect trip now. She has been really well prepared for this race.

“The plan is to run her in the Prix de l’Opera and then if everything goes well we might take her to the Breeders’ Cup for the Filly & Mare Turf, but we will take it step-by-step and one race at a time. The next step will be the Prix de l’Opera.”