Rock Of Gibraltar equalled the feat of Giant's Causeway two years ago by achieving a fifth straight Group One win with an easy success in the St James's Palace Stakes.
The 4-5 favourite, ridden by Michael Kinane, swept to the front a furlong out to score by a length and three-quarters from his stablemate Landseer (13-2) to give trainer Aidan O'Brien his third consecutive win in the race.
Aramram (20-1) was four lengths away in third just ahead of Dupont, who appeared to be short of room on the rails inside the final furlong.
A stewards' inquiry was called - with the winner not affected - but the placings remained unaltered.
O'Brien's third string Sahara Desert set the pace until he was joined on the turn for home by Dupont with Landseer close by.
But Rock of Gibraltar had them both in his sights and comfortably followed up his victories in the Sagitta 2000 Guineas at Newmarket and the Entenmann's-sponsored Irish equivalent at the Curragh.
"He's very dependable. You can set your watch by him," said Kinane.
Winning owner, Manchester United manager Sir Alex Ferguson, said: "I can't say I was apprehensive today, more hopeful because it was a good field.
"And I think the Guineas form has held up so I'm very, very pleased.
"What it shows you is that he can travel in any ground and that's important - soft ground, good ground or good to firm as it was in the Gimcrack - that and his determination.
Ferguson also confirmed that he will retain a share in the colt when he eventually goes to stud.
"It's a great release for me and it can't get better than five Group Ones in a row," he added.