Celestial Halo made all of the running to cause a minor upset in the bet365 Long Distance Hurdle at Newbury.
The nine-year-old, trained by Paul Nicholls and ridden by Daryl Jacob, gave owner Andy Stewart a fifth successive victory in the Grade Two after Big Buck's had won the previous four renewals.
The race was left at his mercy after odds-on favourite At Fishers Cross made a bad mistake at the second-last flight.
Celestial Halo (7-2) went on to score unchallenged by 17 lengths from Medinas, with Reve De Sivola third and At Fishers Cross last of the four runners.
Jacob said: "I love this horse. There's no better pleasure than to win on this horse.
"I'd gone an even gallop, but I didn't think I'd gone a crazy gallop.
"This horse is very, very genuine. He loves galloping, he loves jumping.
"He's an absolute hero - he just loves it."
Nicholls said: "He's been an amazing horse, beaten a short head in a Champion Hurdle, and I thought his price was insulting given his win in France.
"He'll go for the Long Walk at Ascot (December 21) and I'm sure he'll end up in the World Hurdle with Big Buck's."
At Fishers Cross' trainer Rebecca Curtis said: "It's very disappointing, but it's not like he has run a bad race - it was a silly mistake that cost him. He'll go to Ascot next month."
