Wings Of Eagles, trained by Aidan O'Brien and ridden by Padraig Beggy, caused a 40-1 shock in the Investec Derby, as he mowed down Cliffs Of Moher and Cracksman approaching the finish line.
With only two behind him with three furlongs to run, the son of 2011 Derby winner Pour Moi came from the clouds as O'Brien won the Classic for the sixth time.
The result had looked like going with the form book as Cliffs Of Moher just got the better of the two Frankel colts in Cracksman and Eminent inside the final furlong.
But that was not taking into account Wings Of Eagles, the Ballydoyle fifth string, according to the market.
Beggy, having his first ride in the race, said: "That's my first ride, but when you're riding one for Aidan you don't worry about the price, they always have a chance.
"I had a bit of bad luck in running but probably got there at the right time in the end."
There was a strong gallop set by The Anvil and carried on by Douglas Macarthur.
Cracksman - the 7-2 favourite - was never too far away under Frankie Dettori for John Gosden, and did well to stay on like he did.
Eminent made his move down the centre of the track in the hands of champion jockey Jim Crowley, with Ryan Moore taking Cliffs Of Moher on his outside.
But just when Cliffs Of Moher looked to have the race in the bag, Wings Of Eagles, who was second to stable companion Venice Beach in the Chester Vase, hit top gear to win by three-quarters of a length.
Cracksman was another neck back in third.
Beggy added: "A furlong down I thought if I get a run I'd win, I knew Ryan had gone, but in fairness to the big horse his best furlong is his last, which makes a big difference. I don't get to sit on many beasts like this at the races, so I'm going to enjoy it.
"I'd nearly given up on the big days, but Aidan O'Brien has made it happen. It's happy days."
Beggy has fought his way back having suffered a difficult spell in Australia a couple of years ago, where he was handed a riding suspension after testing positive for a banned substance.
He added: "I got into a bit of trouble in Australia and made a mistake. It is something that I've got to put behind me. I was knocked down then and had to pick myself up and come back fighting, and today I think I've proved that."