Frankie Dettori produced a magnificent ride aboard Golden Horn to floor Treve's bid for a historic Prix de l'Arc de Triomphe hat-trick.
Treve was sent off favourite to win the race for the third year in a row, but she had no answer to Derby winner Golden Horn as the mare could only manage fourth.
Golden Horn's victory provided John Gosden with his first win in Europe's premier middle-distance race at Longchamp and capped a stellar season for both horse, jockey and trainer.
Shahah, who had been supplemented into the race to act as pacemaker for Treve, did the job required in setting the pace as Dettori wrestled with how to overcome Golden Horn's wide draw.
Dettori initially kept Golden Horn wide of the field before gradually bringing the son of Cape Cross over to the rail to sit in behind the leader, with Andre Fabre's pair New Bay and Flintshire in third and fourth.
Thierry Jarnet, meanwhile, was slightly worse than mid-division on Treve as he kept the five-year-old on the outside of the field and out of any potential trouble.
Turning for home, Jarnet had brought Treve right into contention on the wide outside as Shahah started to back-peddle, with Golden Horn taking over.
New Bay tried to launch a challenge up the stands' rail as Flintshire, who was second in the race last year, and Treve all attempted to catch Golden Horn.
But Dettori's mount kept on finding more and the Italian was standing high in the saddle celebrating a fourth Arc win after passing the line two lengths ahead of Flintshire.
French Derby winner New Bay just took third from the gallant Treve, who was retired to stud after the race after failing to make Arc history.
