Aidan O'Brien doubles up in Classic trials at Chester

Changingoftheguard shortened dramatically for the Derby after recording a thoroughly impressive display in the Boodles Chester Vase.

Trainer Aidan O'Brien had saddled a record nine previous winners of the Group Three contest, with his Ruler Of The World the last horse to follow up at Epsom in 2013.

O’Brien already houses the ante-post favourite for the premier Classic in the form of Saturday’s 2000 Guineas third Luxembourg.

And while the previously unbeaten New London was the colt expected to emerge as perhaps Luxembourg’s biggest threat with victory on the Roodee, Changingoftheguard had other ideas.

Sent straight to the lead by Ryan Moore, the 100-30 chance soon built up a handy buffer over Charlie Appleby’s favourite New London.

It was clear from before the home turn that the market leader was struggling to bridge the gap and Changingoftheguard galloped all the way up the straight to pass the post six and a half lengths clear.

The winner is a best-priced 10-1 from 66-1 for the Derby.

"He was impressive there and we always thought he’d stay well," said O’Brien.

"He was just chinned in his maiden at Punchestown before he then went and won his maiden really well at Dundalk.

"There was no doubt on our part that he would take a step forward from that and improve for going up in trip.

"The one thing we weren’t sure about today was the ground when it rained as he’s such a fluid mover, but he seems to have handled it fine.

"We were delighted with the run and I think off the back of that, you’d have to say he’d go to Epsom now."

Thoughts Of June (7-1) dominated from the front to provide O'Brien with a seventh victory in the Weatherbys Bloodstock Pro Cheshire Oaks.

Without a win in three previous outings, the daughter of Galileo was last