Treve has won the Prix de l'Arc de Triomphe at Longchamp for the second year running.
The filly, trained by Criquette Head-Maarek, is the first horse since Alleged in 1978 to win consecutive runnings of Europe's richest race.
Jockey Thierry Jarnet, back on board as replacement for Frankie Dettori, surged clear of runner-up Flintshire, with Taghrooda in third.
Treve was retired immediately after the race and will start a breeding career.
"She is amazing, she is a dream," said 65-year-old French trainer Head-Maarek, who brought her stable star back from a run of defeats to land the cherished prize.
"This is a great personal satisfaction for me, this is truly wonderful.
"I couldn't believe the gap that opened for her on the rails and then her burst of acceleration was extraordinary."
|Analysis: BBC racing correspondent Cornelius Lysaght|
|"We should probably have known to keep faith in Treve when Criquette Head-Maarek said we should. "She and her family know all about winning the Arc: Criquette has now won three; her ex-trainer father Alec took the race trophies on four occasions; her grandfather William won a couple; and her brother Freddie was successful in four as a jockey. They are dripping in the race's heritage. "It was still a bold call to insist after Treve's Vermeille fourth that everything would be ok, and she was proved gloriously correct."Big mentions need to be made also of the British pair, Taghrooda and Kingston Hill, in third and fourth. Both were drawn unfavourably wide in the stalls."|
The 11-1 winner had been written off in many quarters after three successive defeats, but an electric burst of pace saw her burst through to win by two lengths.
Flintshire, for seven-time winning trainer Andre Fabre, ran creditably in second, as did the British-trained pair of Taghrooda (third) and Kingston Hill (fourth).
Treve will now go to stud for Qatari owner Sheikh Joaan al Thani, of Al Shaqab Racing,
"I think it's off to the Sheikh's stud farm in Normandy and deciding who will be the lucky husband, or husband number one!" said Al Shaqab racing advisor Harry Herbert.
Dettori had some consolation later on when he guided Olympic Glory, trained by Richard Hannon, to a last-to-first success in the Prix de la Foret.
Qatar Prix de l'Arc de Triomphe Longchamp
1 Treve (Criquette Head-Maarek) Thierry Jarnet
4 Kingston Hill
5 Dolniya, 6 Harp Star, 7 Prince Gibraltar, 8 Just A Way, 9 Ruler Of The World, 10 Al Kazeem
11 Avenir Certain, 12 Siljan's Saga, 13 Tapestry, 14 Gold Ship, 15 Chicquita, 16 Spiritjim, 17 Ectot, 18 Ivanhowe, 19 Free Port Lux, 20 Montviron.
Distances: 2l, 1 1/4, 3/4. 20 ran