Enable had to make do with the runner-up spot in her bid for history and a third victory in the Qatar Prix de l'Arc de Triomphe as Waldgeist provided Andre Fabre with a record eighth success.
Having stretched her Group One tally to 10 with victories in the Coral-Eclipse, the King George and the Yorkshire Oaks this season, all eyes were on John Gosden's brilliant mare as she aimed to become the first three-time winner of Europe's premier middle-distance contest.
Frankie Dettori had to niggle the 4-6 favourite along during the early stages, but she was back on the bridle at the top of the home straight and looked well positioned to race into the record books.
Once asked to quicken, Enable did manage to pull clear - and the packed grandstands in Paris roared in expectation.
However, her stride began to shorten in the final furlong on the testing ground and she was unable to resist the fast-finishing 16-1 shot Waldgeist - fourth in last year's renewal and beaten by Enable on each of the three previous occasions they had met.
Gosden was full of praise for both the winning connections, and his own vanquished heroine.
"She ran an absolutely brilliant race," he told ITV Racing.
"Waldgeist came late and strong - it was a good pace up there.
"Frankie committed, and went for it, and just the last part, in the ground testing her, it's hard to show that explosive turn of foot - and Waldgeist has outstayed her on the ground.
"Full marks to Andre."
Reflecting on the 16-1 victory, Fabre said: "I'm very proud that Waldgeist managed to beat such a fantastic mare - I'm delighted."