French challenger Giofra claimed the Etihad Airways Falmouth Stakes at Newmarket for Alain de Royer-Dupre and Christophe Soumillon.
The Andre Fabre-trained Golden Lilac was sent off the odds-on favourite to build on her comeback victory at Longchamp, but she ran deplorably as her compatriot stole the show.
For a long way it appeared man of the moment John Gosden may register yet another big-race triumph as Elusive Kate kicked for home over a furlong down, but 10-1 shot Giofra soon went in pursuit.
Elusive Kate (25-1) under Frankie Dettori did not go down without a fight and ran a stormer on ground softer than ideal on her seasonal return, but Giofra was half a length too strong.
A third French-trained participant, Francois Doumen's 33-1 chance Siyouma, was third.
Soumillon said: "The pace wasn't that quick, I wouldn't say I wasn't happy but a quicker pace would have been better as she was a bit keen.
"When I asked her to go at the two-furlong marker she was going very well and I knew I just had Frankie to beat."
