Cheltenham Gold Cup winner Denman has been retired after suffering a setback in his preparation for the Lexus Chase.
The Paul Nicholls-trained 11-year-old was due to make his seasonal reappearance in the December 28 feature at Leopardstown but a tendon problem has scuppered those plans and ended his career.
"It is with great regret that I have to announce the retirement of Denman," Nicholls told his Betfair column.
"A scan yesterday afternoon revealed tiny damage to his near fore tendon, so this morning marks the end of an era for Ditcheat."
Nicholls continued: "Denman was great on Wednesday morning as he worked towards his intended start in the Lexus later this month, but he pulled up a little bit sore yesterday morning and Clifford wasn't happy with him.
"So we called Buffy (our vet) in to scan him at 4pm yesterday afternoon, and that revealed the problem with his near fore tendon.
"We immediately informed his owner Paul Barber who, after consulting those close to him, took the decision to retire him.
"It was the only course of action to take.
Denman enjoyed a successful career in novice hurdles but marked himself as a real star when switching to fences and destroying his rivals by 10 lengths and more in the Royal & SunAlliance Chase at the 2007 Cheltenham Festival.
He followed up that victory with a wide-margin win under top weight in the Hennessy at Newbury in December that year, before going on to claim the Lexus Chase.
Denman then enjoyed a showdown with stablemate and reigning champion Kauto Star in the Cheltenham Gold Cup the following March, with Denman galloping to glory by seven lengths under Sam Thomas, although his old rival reversed that form in 2009..
Nicholls' charge turned in a truly memorable weight-carrying performance to win a second Hennessy in 2009, competing off a 13lb higher mark than in 2007 and giving nearly a stone and more to each of his rivals.
That was to be Denman's final victory, although he chased home Imperial Commander in the 2010 Gold Cup and filled the same position behind Long Run last March.
He was last seen when finishing a lacklustre fifth in the Bowl at Aintree in April and while he will no longer be in training, he will be stabled with Nicholls until the end of this season.
"We are all devastated here at Ditcheat but Denman has given us some wonderful moments on the track, winning a Gold Cup, finishing runner-up in three more, as well two Hennessys, a Lexus and a SunAlliance Chase," said Nicholls.
"He will be given an honourable retirement. But for the immediate future and to help his great friend Kauto Star, he will be kept in his box next to Kauto for the rest of season.
"Denman will always be a legend here at Ditcheat.
"So this truly is an end of an era."