Lope De Vega romped away with the Prix du Jockey Club (French Derby) at Chantilly to follow up his victory in the French 2000 Guineas.
Always prominent, he slipped his field early in the straight in the hands of Maxime Guyon and quickly pulled several lengths clear.
None of his rivals got near enough to put in a challenge and the Andre Fabre-trained colt scored easily by three lengths from Planteur, with Frankie Dettori third on Paid Perdu.
Ryan Moore, bidding to follow up his Epsom triumph, had Ice Blue handy, while Brian Meehan's Dancing David and Ballydoyle pair Viscount Nelson and Cape Blanco were also well placed, but it was a one-horse race once Lope De Vega hit the front.
Fabre said: "I had a doubt about him staying. He is from a Machiavellian family, so there was a question mark there. I am tempted to drop him back to a mile for the Marois (at Deauville in August). It is better to run over too short than too far.
"He is an excitable kind of horse, so I don't want to travel him too far, but if he stays in training as a four-year-old - and there is a strong possibility he will - he could then possibly have a race in England."
Guyon added: "It was always the plan to stay up with the pace. I knew the horse had loads of pace, so straight away I was able to get a good position.
"I was on the French 2000 Guineas winner, so I knew I was on a good horse and I knew he would run well. It was a surprise that no one came to me to give chase in the straight. I have ridden some very good horses, but this horse is special."
Dettori, delighted with the effort of Pain Perdu, said: "We thought if we were in the first four it would be an achievement as it looked a very hot race, and we have managed to finish third, which is great. The winner put up a fantastic performance."
Cape Blanco finished 10th, with stablemate Viscount Nelson fifth, and Aidan O'Brien said: "I didn't really see what happened during the race, but Cape Blanco loves fast ground and Johnny (Murtagh) said he didn't pick up on the ground out there, so I don't really know what happened."