Major Cadeaux led all the way to beat odds-on favourite Dutch Art in the Lane's End Greenham Stakes at Newbury.
Richard Hughes set a steady pace on Richard Hannon's 100-30 shot, with Dutch Art hot on his heels.
But the ante-post second-favourite for next month's 2000 Guineas, who came into the race with an unbeaten record, could not get to grips with his rival.
Major Cadeaux powered clear to win by three and a half lengths with Halicarnassus a length away in third.
Richard Hannon junior, the trainer's son and assistant, said: "We've always thought he was a very good horse, but he had his problems after Royal Ascot last year.
"I'm delighted with him. I thought he might need it a little bit. It wasn't planned for him to make the running, but he's gone and done it very well.
"I've no doubt he's the best horse in our place for the last few years. Of course I fancy him for the 2000 Guineas, but my only concern is for the ground."
Dutch Art's odds for next month's race at Newmarket have drifted out to around 7-1 with Major Cadeaux now as short as 5-1.
Dutch Art's trainer Peter Chapple-Hyam said: "It turned into a complete sprint and that didn't suit my horse. It will be a lot different in two weeks' time."
Greenham Stakes (Newbury)
1. Major Cadeaux (R Hughes) 10-3
2. Dutch Art (J Fortune) 8-11 Fav
6 ran