Castle Harbour came up short in his attempt for a third straight victory in the group three Jersey Stakes at Royal Ascot,

The Bermudian-owned thoroughbred, a 9-2 favourite, finished sixth in very competitive field, with Ribchester, who won last year’s Mill Reef Stakes, romping home to an emphatic victory in the seven-furlong race.

Castle Harbour has enjoyed a superb start to his career, winning the Alex Scott Maiden Stakes at Newmarket in April before storming to victory in the Conundrum HR Consulting Stakes at York last month.

He was favourably drawn in stall nine of the 19-runner field but could never get on terms with Ribchester, a 7-1 joint-second favourite, his stablemate in the John Gosden yard with different connections.

Harry Herbert, the racing manager of Highclere — the racing syndicate in Berkshire that oversees the Bermuda Thoroughbred Racing operation — said Castle Harbour had delivered a “respectable” performance.

“It was clear before the race that this was going to be one of the hottest renewals of this contest for many years with professionals who were at Ascot describing it as more of a group two in terms of the standard of the field,” Herbert said.

“Frankie Dettori [the horse’s jockey] was very complimentary after the race saying that Castle Harbour was still very much on the up and probably lacked the experience of other horses in the race.”

Ribchester, who is also a three-year-old, is trained by Richard Fahey and owned by Godolphin.

Castle Harbour is part of BTR’s second syndicate, the Pink Sands account, along with Sir George Somers.