Ben Pauling’s classy staying hurdler was pulled up by David Bass after seven fences of the Steel Plate And Sections Novices’ Chase, in which he was sent off favourite.
Barters Hill, whose only previous defeat came in the Albert Bartlett Novices’ Hurdle at last season’s Cheltenham Festival, was found to have been lame behind and was taken away for further assessment.
Pauling revealed the horse’s injury is not career-threatening.
“The horse has slipped a tendon off his hock. It’s not career-ending, but he will need a certain amount of time off,” he said.
“Whether he’s back this season depends on how severe it is. A horse like that needs plenty of patience. It’s a terribly sad day, but we’ve still got him. It’s a real shame, but hopefully it’s only a stumbling block.”
O O Seven (9-2) took full advantage of Barters Hill’s dramatic exit as he ran out a convincing winner, despite drifting badly towards the stands rail on the run-in.
Jockey Nico de Boinville soon had the Nicky Henderson-trained six-year-old back on an even keel and O O Seven galloped past the post 10 lengths to the good over Sizing Tennessee. Rock The Kasbah ran on strongly to claim third place.
“He’s a gorgeous-looking horse and this is what we’ve been waiting for,” said Henderson. “This is where his life really begins. It’s a long wait but you have to be patient. Hopefully, Barters Hill will be all right. It take a lot of gloss off the race as he was the horse we had to beat and it would be sad if they can’t race him for a while.
“It left the race wide open and our fellow was there to grab his opportunity.”