The Cheltenham Gold Cup hero then took a crashing fall at Becher's Brook and despite getting up and running away, later had to be humanely destroyed.

Frank Berry, racing manager to owner JP McManus, said: "It's just of those things. The horse looked perfect when he got up from the fall and he galloped away and jumped away afterwards.

"When he was up and running again you'd be hoping he'd be fine afterwards, they usually are, but what happened happened and it was very sad.

"It's a sad day, particularly for everyone in Jackdaws (Castle, O'Neill's yard).

"He was always a popular horse in the yard, even before he won the Gold Cup. I don't want to say much more about it, it's just very sad."

Berry was delighted with the run of Sunnyhillboy and hopes he can return in a year's time.

He said: "He got a great ride from Richie (McLernon) and jumped great. He looked like he'd get there and the other horse basically outstayed him.

"It was just on the nod and one of things, you'd be hoping he might be back there for another crack next year."