Gleneagles has become the eighth horse to complete the English and Irish 2000 Guineas double, giving trainer Aidan O'Brien his 10th success in the Irish version at The Curragh.

Ridden by Ryan Moore, Gleneagles won in impressive style on Saturday, prevailing by three-quarters of a length from Endless Drama with the Richard Hannon-trained Ivawood third.

O'Brien, who has completed the Guineas double three times, has seen one after another of his leading Epsom Derby fancies fall by the wayside.

He said Gleneagles was not certain to go to the blue riband as he believed the mile (1600m) of the Guineas was his best distance.

"He has always worked like a miler, he's strong and quickens very well," O'Brien said.

"He's never had to show the kind of courage before that he showed today.

"The Curragh is a tough mile in that (slow) ground. It was very borderline that he ran."

Gleneagles' owner, Coolmore Stud proprietor John Magnier, also indicated the Derby was unlikely.

"The next thing is probably to think about the St James's Palace. We will take it step by step," he said.

"We paid for the option (of the Derby), so we are hardly going to declare it today without being clever about it, but it's unlikely.

"We'll have to discuss it with Michael (Tabor), Derrick (Smith), Aidan and all the lads, but it looks pretty obvious."