Aidan O'Brien believes Investec Derby hero Wings Of Eagles ran an "incredible" race to finish third in Saturday's Irish Derby despite sustaining a career-ending injury.
The Pour Moi colt was a shock 40-1 winner of the Epsom Classic at the start of June and aimed to become the Ballydoyle handler's fifth dual Derby winner at the Curragh.
He was beaten just half a length in third behind stablemate Capri and John Gosden's Cracksman, but it proved to be his final racecourse appearance.
O'Brien said: "You're always worried when they pull out and he pulled out very sore this morning.
"When the lads X-rayed him, his sesamoid had completely come apart. It's incredible he ran the race he did with that.
"We're very sorry to lose him because he was a very unusual horse in that he stayed very well but quickened very well.
"It's just one of those things. It's a pity."
Wings Of Eagles made his racecourse debut at last summer's Galway Festival, finishing down the field, before opening his account at Killarney.
He kicked off his three-year-old campaign by finishing second to stablemate Venice Beach in the Chester Vase before his surprise victory at Epsom in the hands of Padraig Beggy.
Beggy was replaced by Ryan Moore on Saturday.
In all he won two of his seven starts and earned over €1million in win and place prize-money.
A statement issued by Coolmore to Press Association Sport read: "Epsom Derby winner Wings Of Eagles was found to be lame this morning after running in the Dubai Duty Free Irish Derby at the Curragh yesterday.
"He was examined today in his box in Ballydoyle by the attending veterinary surgeon who diagnosed a fracture of his left front sesamoid.
"Sadly this is a career-ending injury."