Harzand and Pat Smullen (left) get the better of Idaho and Ryan Moore© Photo Healy Racing
Harzand put in a performance full of courage to become the eighteenth horse to complete the Dubai Duty Free Irish Derby, Epsom Derby double.
Successful at Epsom just three weeks ago today, the son of Sea The Stars was sent off the 4/6 favourite in the famous silks of the Aga Khan.
The brown colt was settled in third as stable mate Ebediyin set the pace.
Pat Smullen then produced the winner to lead with over two furlongs to race, and he was ridden with over a furlong to go as Idaho came with his challenge.
The duo had a great battle from there, with Harzand getting on top in the closing stages, going on to prevail by half a length.
Idaho (11/4), who was of course third at Epsom, had to settle for second under Ryan Moore for Aidan O'Brien, while recent Ulster Derby winner Stellar Mass (33/1) was a further three and three parts of a length back in third under Kevin Manning for Jim Bolger.
Weld, who was recording his third win in the race, said afterwards: "I knew Aidan would have his horse (Idaho) in tremendous order and that he'd be better than Epsom so I knew we'd have to be at our very best and also better than at Epsom to win.
"It was a magnificent race and he showed speed today. People said he didn't have the speed but he showed it today and the two horses picked up and quickened.
"The first two improved considerably from Epsom. They just didn't quicken once, they quickened twice
"Idaho is a high class horse and it was a proper horse race.
"It was a great ride from Pat and we saw two jockeys at the top of their profession ride brilliant races. It was horse racing at its best.
"I was concerned because he had a very hard race at Epsom. We always knew he was very tough but he had to be 110 percent today.
"I'll give him a well-deserved break now and train him for the Arc.
"This is a very, very special race and I've been enjoying it since I was a child. I've been fortunate enough to win it three times now (Zagreb in 1996 and Grey Swallow in 2004)."
Pat Smullen, who was recording his second win in the race, added: "It is a big relief, the pressure was on and he is a dual Derby winner now.
"You can give horses good rides and bad rides but when they are as good and determined as this lad it makes it easy.
"There is no knowing where this horse will end up, he is so tough. He is not just tough, he has got pace, he is a very, very good horse and I'd love to think he will be an Arc horse now.
"He was very courageous over the last furlong. When I needed him he really responded and pulled out all the stops. I don't think I've ever rode such a courageous horse.
"Ryan came with a well-timed run and the plan was to put it up to him. Our horse is a very, very good stayer and has a lot of stamina. The tactics came off.
"I just can't get over his courage in the last half furlong."
The Aga Khan said: "He is very good. It's a wonderful family.
"We checked him with all our mares, he will mate very well, and when he goes to stud we will be right behind him. Things are shaping up very well.
"I'm not sure we really know his limits. I don't think we saw the best of the horse here or at Epsom, I think he can do more.
"We had one element which we were confident about, and that was he was going to get the trip."
Paddy Power now go 8/1 (from 10’s) about Harzand for the Arc, while Idaho is available at 20’s (first show)
Additional reporting by Gary Carson
