Capri won the Irish Derby at the Curragh to give trainer Aidan O'Brien his 12th success in the Group One race.
The 6-1 shot held off the challenge of Cracksman, favourite Wings of Eagles and Waldgeist to give jockey Seamie Heffernan a third Irish Derby victory.
Capri, who was sixth in the Epsom Derby in June, was one of five horses trained by O'Brien among the nine-strong field.
Wings Of Eagles, ridden by Ryan Moore, could not repeat the Derby double achieved last year by Harzand.
The Anvil set the pace for the early part of Saturday's race under Ana O'Brien but Capri stayed well and produced a strong finish.
The grey Galileo colt won by a neck in a thrilling finish.
John Gosden's Cracksman, the only British-trained representative in the line-up, was close behind, with French Derby runner-up Waldgeist fourth.
BBC horse racing correspondent Cornelius Lysaght
The rain-softened going at the Curragh - officially good to yielding - was maybe the key to this thoroughly gutsy victory by Capri.
At Epsom, when sixth, the colt, another Classic-winning son of Coolmore's super-stallion Galileo, hung slightly off a true line, perhaps 'feeling' the firmer conditions that day.
Here, after being pushed into the lead with over a quarter-mile to go, the second and third - who'd been in front of him at Epsom - both had a crack at him, but the winner was simply not for passing, giving Aidan O'Brien a 12th win, 20 years after the first.
Irish Derby result
1 Capri (J A Heffernan) 6-1
2 Cracksman 3-1
3 Wings Of Eagles 2-1 Fav
4 Waldgeist 3-1
Maiden win for Gordon
Elsewhere, jockey Josephine Gordon celebrated a breakthrough first success at flat racing's Group-race level when successful on 8-1 shot Koropick in the Chipchase Stakes at Newcastle.
Gordon delivered the horse, trained by Hugo Palmer, in the very closing stages to continue her good run since graduating from champion apprentice to fully fledged rider.