Aidan O’Brien’s Order of St George repeated his 2015 Irish St Leger triumph as he clinched a nine-length victory at the Curragh.
Order of St George becomes only the fifth horse to win the race on two occasions and also finished runner-up in the Irish classic 12 months ago.
Ryan Moore’s mount justified his 2-5 favouritism as he finished way ahead of 14-1 shots Torcedor and Mount Moriah.
The Queen’s second favourite Dartmouth finished well off the pace.
“He’s an incredible horse. He’s got everything,” said victorious trainer O’Brien after the race.
Moore kept Order of St George in the middle of the pack as English raider Lord Yeats made the early pace but there was only going to be one outcome once the winner took the lead with three furlongs remaining.
Aidan O’Brien’s charge was an 11-length winner of the one-mile-six-furlong Classic in 2015, but suffered a shock reverse at the hands of Wicklow Brave when a 1-7 favourite 12 months ago.
The five-year-old came within a short-head of claiming back-to-back renewals of the Gold Cup at Royal Ascot in June, going down after a thrilling tussle with Big Orange.
Wicklow Brave, who went off at 10-1, finished in fourth spot.