Outsider Tornado Flyer was a surprise winner at the King George VI Chase at Kempton Park on Sunday.
Trained by Willie Mullins and ridden by his nephew Danny, Tornado Flyer came home nine lengths clear of dual winner Clan Des Obeaux, while Cheltenham Gold Cup star Minella Indo and favourite Chantry House missed the mark.
Tornado Flyer grabbed the lead at the penultimate fence and when Asterion Forlonge crashed out at the last, Clan Des Obeaux was left in second with Saint Calvados third and Frodon fourth.
"I didn't think he was totally out of this," said Danny Mullins, who was completing a double on the day.
"It was as competitive a race as has been run all year in England and this lad has always had the promise to deliver something like this.
"I knew we had a squeak and from going away for the second circuit I was starting to come alive. Halfway down the back was able to take him back and fill him up.
"Going to the last in front he was idling and I wouldn't have minded Asterion coming to me as I think I had a little more left.
"But I was happy enough to be left in front too. When you're riding for Willie you've always got a chance - no matter what price they are."
Clan des Obeaux stablemate Saint Calvados produced a terrific run in his first race for trainer Paul Nicholls to finish third, one better than last year.
Defending champion Frodon - also trained by Nicholls - was unable to reproduce his pillar to post victory under Bryony Frost as they approached the final turn.
He finished a distant fourth with his lack of bite possibly due to a battle up front at a fierce pace for the first half of the race with Cheltenham Gold Cup winner Minella Indo.
Victory - that came with a winners cheque of £142,000 ($190,000) - for Tornado Flyer in what is considered the second most prestigious steeplechase in England after the Cheltenham Gold Cup came 20 years after Willie won with Florida Pearl.
Willie is keeping his fingers crossed his upward trajectory continues in the new year, adding: "We changed a few things with him this year and he seems to be improving.
"He always promised, but never delivered in the second half of the season. Maybe he's going to this time. John Turner is in charge of plans after getting me to bring him over, but I imagine he'll be entered in all those Grade One races. Maybe he's just better going right-handed, I don't know."