Loch Garman lunged late to grab Group One glory for Jim Bolger in the Criterium International at Saint-Cloud.
Ralph Beckett's horse Anna's Pearl made most of the running in first-time blinkers, and looked the most likely winner when seeing off US Law at the top of the home straight.
Loch Garman, who only made a winning debut at Navan a week ago, was ridden far more patiently by Kevin Manning, but the jockey was rowing along by the time they rounded the final bend.
Despite running green once switched wide, the son of Teofilo really found top gear in the final furlong and swept by the Jim Crowley-ridden Anna's Pearl to take top honours.
US Law was third.
Hughie Morrison's British raider Chil The Kite was well beaten in the Group Three Prix Perth over a mile.
Don Bosco took top honours, with favourite Pollyana fourth and former John Oxx inmate Takar, now with Rod Collet, sixth.