Diego Velazquez got the measure of his stablemate Capulet to give Aidan O'Brien a 10th success in the Group 2 KPMG Champions Juvenile Stakes at Leopardstown.

Capulet attempted to stretch Diego Velazquez swinging for home but Seamie Heffernan was first to go for the whip on the leader a furlong and a-half down.

The pursuer, Diego Velazquez, was grinding away at the deficit and was ridden by Ryan Moore to head Capulet at the furlong pole.

The pair had the finish to themselves and it was Diego Velazquez who saw it out best from the game runner-up. The 8/15 favourite prevailed by half a length from the 9/1 runner-up.

Both Diego Velazquez and Capulet won on debut, so it is Diego Velazquez who retains his unbeaten record. He made 2.4 million guineas at Tattersalls in October last year.

“We're very happy. We liked the second horse a lot and we knew we needed something to take him and stretch him a little bit,” said O'Brien.

“They didn't go very fast for the first half and turned it on from halfway, so he learned a lot.

“Ryan was delighted, he said he had to catch hold of him and make him learn. He's still a baby.

“We were surprised the first day that he ran in the Curragh how babyish he was, he never took a hold of the bridle.

“Today he was green as well, but a lot better. We think the race will leave him in a very good place.

“I'd imagine he'll go for the Racing Post Trophy, that's what we thought he would do.

“We think he's going to step up loads from it but we were very happy with what he did today.

“The plan was to come here and then go to the Racing Post.

“We did it with Auguste Rodin last year, but we knew this horse had to learn a lot more than Auguste did last year.

“He was extra green at the Curragh and we knew unless he was going to learn a lot this time it was going to be very hard to pitch him into a good race after that. We think he will.”

On the runner-up he added: “He's a good horse. He won first time at Dundalk and we liked him. He's out of a good Galileo mare and we thought he was a fair horse.

“Seamus liked him a lot today. He's a typical Justify, the minute you go beyond seven furlongs they seem to grow another leg. They are really classic-bred middle distance horses and you'd have to be really happy with him also.”

“At the moment it's the plan (to run both in the National Stakes). We're happy with both at the moment.”

Paddy Power trimmed Diego Velazquez from 12/1 to 10/1 for the 2,000 Guineas and from 9/1 to 7/1 for the Derby.

Additional reporting by Gary Carson