Christophe Soumillon had to sit patiently aboard the winner and wait for a gap to appear.

But when the split did materialise, Dylan Thomas quickened smartly.

O'Brien's charge scooted clear of runner-up Irish Wells, while Doctor Dino stayed on from the rear to claim third in the Group One contest.

Dylan Thomas was taking his Group One haul to three in the first top-flight contest of the year, having won the Irish Derby and Irish Champion Stakes last year.

Although Dylan Thomas temporarily had nowhere to go after Irish Wells hit the front, those who supported him at 4-9 were soon breathing easily once Soumillon extricated him from a pocket.

Irish Wells (5-1), fifth in the Prix De l'Arc De Triomphe last year, chased him in vain but comfortably held 16-1 chance Doctor Dino to secure second place.

The Danehill colt's easy two-length victory in the Prix Ganay impressed William Hill, who trimmed him to 6-1 from 7s in their ante-post market for the Arc later in the year.

Soumillon was left starry-eyed by Dylan Thomas' success and enthused: "He is a real Group One horse.

"He has progressed and will progress more and is in another category to the others in the race.

"He is a surprising horse as he is never tired and has huge potential.

"He may not be quite in Hurricane Run's class, but he is up there and I would expect he will go for the King George."

Irish Wells' connections were happy with their charge and revealed a trip to Epsom could now be on his agenda.

"We were beaten by a very good horse," admitted owner Berend van Dalfsen.

"We are very happy with him as he is a lot calmer than last season.

"I would see him running in the Coronation Cup and the Grand Prix de St Cloud and then we will look at the rest of the campaign."