Yet another wonderful ride from Ryan Moore aboard The Grey Gatsby was enough to secure a first British-trained winner of the Prix du Jockey Club at Chantilly since 2005.
The French Derby has tended to be dominated by the home contingent, but Kevin Ryan's colt proved his success in the Dante at York was not a one-off as he quickened three lengths clear of Shamkiyr and the luckless favourite Prince Gibraltar.
The Grey Gatsby, who was sent off at 18.9-1 on the French Tote (12-1 industry SP), appeared to get warm before the start and was not immediately in position but took up residence in the middle of the field as Prestige Vendome and Mr Pommeroy set the pace.
Moore moved towards the rail, finding a perfect opening approaching the final furlong, and The Grey Gatsby picked up well in what was the quickest ever time for a race which was moved back to an extended 10 furlongs when Shamardal struck for Godolphin nine years ago.
It was a first victory in the event for Moore, and a first major European Classic for North Yorkshire-based Ryan, whose biggest prizes to date have largely come with two-year-olds.
As is often the case, it was a rough and tactical affair and the most obvious hard luck story came with the highly-rated Prince Gibraltar, who was stuck at the back of the field before making late ground under Gerald Mosse.
Shamkiyr took second place for the Aga Khan, while the other British raider Ayrad was only 11th. The French Guineas winner Karakontie appeared not to stay and finished eighth.
Ryan said: "We always thought he was a good horse and after the Dante Ryan thought that the French Derby would be the right race for him.
"I don't think he got the credit he deserved after the Dante Stakes. Obviously it's great to win a French Classic.
"He will have a break now for a couple of weeks and then there would be the Juddmonte International to consider."
Asked if he thought he would stay further, Ryan said: "I don't see any reason why he wouldn't stay. He doesn't have an entry in the Arc, but yes, we would consider supplementing him."
Owner Frank Gillespie was overwhelmed, and said: "It's great to win this race, it means a lot to us. I have about six horses in training with Kevin and I would like to thank Ryan who rode him so well today. I think I would like to go to York with him next."
Moore explained his strategy when he said: "This is the second time that he has run over this trip and he won really well.
"He broke well and as usual it was a bit messy early on with everyone trying to get off the rail and I actually went back to the rail.
"Once he got his position he found his rhythm and when we got into the straight I thought he would win. He showed a good turn of foot."
Jean-Claude Rouget is likely to step Prince Gibraltar up in trip for next month's Grand Prix de Paris.
Earlier, Andre Fabre claimed his 11th victory in the Prix de Royaumont - but not with the runner many expected.
The master French trainer saddled half of the six-strong field for the Group Three event for three-year-old fillies over a mile and a half and much the shortest price of the trio was Khalid Abdullah's Delivery.
Pierre-Charles Boudot and recent course winner Savanne had other ideas and dominated from start to finish, while the Pia Brandt-trained Ball Dancing stayed on for second.
Fabre quickly added another Group race to his haul after an impressive performance from the Godolphin-owned Fintry.
All eyes were on hot favourite Veda, who was unable to follow up on her fine second in the French 1000 Guineas and finished out of the frame.
Veda's stablemate Zavallya set a decent gallop and Maxime Guyon sat just in behind aboard Fintry, who easily won a Listed race over course and distance three weeks earlier.
Taking the lead at the top of the home straight, she held off all-comers in game fashion.
Christophe Soumillon demonstrated his talent from the front with a riding masterclass on Spiritjim in the Grand Prix de Chantilly.
Pascal Bary's colt has now won his previous four starts but this Group Two was his most prestigious victory to date.
Spiritjim was always in the lead and weathered the severe pressure from Now We Can in the final furlong to just hold on as the post arrived.
The trio of British runners in the Prix du Gros-Chene filled the last three places as the home team came out on top.
Stepper Point, Justineo and Lucky Beggar were all in contention but the improving three-year-old Rangali shot clear in the closing stages.