Racing: New Approach, only revealed as a intended runner in the Derby five days before the race, showed his undoubted class with a game victory in the Epsom showpiece.
His Co Carlow trainer Jim Bolger had said at a media event in April he was an unlikely starter and admitted the week before the race he left the horse in the Classic "by mistake."
However, buoyed by the way his champion two-year-old had come out of the Irish 2000 Guineas, in which he had finished second, and by the ground conditions at Epsom, Bolger recommended to Sheikh Mohammed, husband of owner Princess Haya of Jordan, last Sunday that New Approach take his chance.
"There is no need to emphasise the mistake. It was the biggest mistake I have made in a long time. But it was fortuitous and it has worked out for the best," Bolger explained. "I am just extremely lucky and thankful I did make the mistake.
"I admitted the mistake from the word go and I don't see why people should have had such a big problem. I put my hands up and admitted the mistake.
"It (winning the Derby) is very special. I thought before the race it would be up there with the best. I very willingly say (now) it is the best."
New Approach (5-1) just held the persistent challenge of Michael Stoute's Tartan Bearer (6-1), ridden by Ryan Moore, by half a length to give Bolger, 67, and jockey Kevin Manning their first success in the Derby.
Another Irish runner, Casual Conquest, the 7-2 favourite, was four and a half lengths away in third.
New Approach can be fractious and there had been plenty of talk beforehand about him being ponied (accompanied by a stablemate) down to the start, something which caused a delay in the Newmarket Guineas.
But there were no dramas to speak of on that front this time and Bolger said: "Everything was very calm and it all went according to plan. There was no excitement or anything else, he just got the job done.
"Coming up from the stables we noticed he had picked up a little bit of paper on his foot. We got rid of that, although that was a mistake in itself as when we stopped to pick out his foot he stopped. After that he walked on and we didn't have too many anxious moments after that.
"I knew he would lob down (to the start) as we have been settling him recently and I was never too concerned about that.
"Kevin really starred, he kept his cool and did everything right. He didn't panic, he had a huge job trying to manage him and steer him and he got it done in great style. This is one we owe to Kevin."
Stoute, who had three runners, said: "I am delighted with them. I thought we might have won, but I had a terrible view and I would like to see it again."
Casual Conquest's trainer Dermot Weld said: "The horse has done me proud. He was obviously inexperienced but for the third ever run of his career, he has come to fruition.
"I think it was a very good Derby and I don't want to take anything away from the winner who is an exceptional horse. The next stage is probably for a rematch in the Irish Derby."