No More Heroes had to be put down on Wednesday night after suffering a tendon injury in the RSA Chase at the Cheltenham Festival.
The Gordon Elliott-trained seven-year-old had scored twice at Grade One level this term and was sent off as the second favourite for the three-mile affair.
However, it soon emerged after he had faded into fourth that all was not well as jockey Bryan Cooper dismounted and a veterinary officer later reported the Gigginstown House Stud-owned gelding had struck into himself on his left fore.
Connections had hoped he could be saved, but Gigginstown confirmed on Thursday morning that his injury had proved too severe.
A statement on Thurday morning read: "Unfortunately the injury to No More Heroes, having struck into himself and damaged a tendon yesterday, proved to be too significant to save him.
"Having consulted with the vets at the equine hospital, and after extensive care and assessment, it was considered that it would be in the horse's best interest that he be humanely put down, and this was carried out late last night."