John Gosden and Mark Johnston had already enjoyed varying degrees of success on the card in France prior to the Listed contest over a trip just shy of one mile seven.
However, neither Thimaar nor Gulf Of Naples were able to play a leading role in a race which went to Lone Ranger, trained by Alain de Royer-Dupre.
The four year-old was held-up in the rear in the early stages before being produced by Soumillon in the final stages of the contest and the pair scored a narrow success from Flamingo Fantasy and Inside Man who had beaten the winner over two miles in June.
Thimaar fared best of the two British trained runners in a close-up fifth under Paul Hanagan with Gulf Of Naples back in seventh.
Elusive Kate gave jockey William Buick and trainer John Gosden yet another Group One winner in a golden summer after making all the running in the Prix Rothschild.
Narrowly beaten on her belated reappearance in the Falmouth Stakes at Newmarket, Elusive Kate already had positive experiences of the Normandy course as she landed two events there last year.
Buick was able to dictate just a steady pace and was never really challenged until the final furlong, when Andre Fabre’s Golden Lilac was released for her run, but Elusive Kate already had the prize in the bag.
The Buick and Gosden combination have already combined for other Group One victories this year with Great Heavens (Irish Oaks), Izzi Top (Pretty Polly Stakes), Fallen For You (Coronation Stakes) and Nathaniel (Eclipse).
Golden Lilac, considered by Fabre as the best filly he has handled, was a bitter disappointment in the Falmouth and looked more like her old self in finishing a length and a quarter behind.
Mashoora was third ahead of Sagawara with Immortal Verse, last season’s Coronation and Jacques le Marois winner, making very little impression in last on her comeback.
The mile event for fillies, formerly known as the Prix d’Astarte, was for once taking place without the presence of the brilliant Goldikova, who was retired last year having completed four consecutive victories.
Earlier on, British raider Baileys Jubilee came up just short against Mazameer in the Prix Cabourg.
Mark Johnston’s filly was making a quick return to France after landing a Listed race at Vichy a couple of weeks ago and threw down the gauntlet to Mazameer.
But Freddie Head’s colt was too difficult to pass and held her off by a short neck.