Denman destroyed his rivals to win the totesport Cheltenham Gold Cup.
Ridden by Sam Thomas, the 9-4 chance took over at the head of affairs with just over a circuit to go and he poured on the pressure up front.
Reigning title-holder Kauto Star looked in trouble coming down the hill but finished well for second, while Neptune Collonges flew for third, giving trainer Paul Nicholls a famous one-two-three.
The eventual third set a decent clip through the early stages but a flying leap from Denman propelled him into the lead at the 11th obstacle.
Thomas was always sitting confidently from that point, while Kauto Star, who had worryingly brushed through a number of fences at that stage, was in a decent rhythm himself.
However, the epic duel the racing world had waited for all season never really materialised as Denman and Thomas gradually turned the screw.
Having appeared to jump the third-last with a mountain to climb, Kauto Star (10-11 favourite) did begin to make some inroads into Denman's lead.
But while the winner's stride began to shorten a touch after the penultimate obstacle, a good jump at the last sealed a seven-length success.
Kauto Star responded to Ruby Walsh's urgings in gutsy style but was under pressure for second late on as Neptune Collonges got to within a short-head at the line.
Thomas told Channel 4 Racing: "I don't know what to say, I'm lost for words again. What a horse.
"He wasn't doing a tap in front, he just stays and stays.
"I went through the race in my head a million times before and it just went absolutely according to plan.
"He's just such a good horse and travelled so well for me."
Nicholls added: "That was brilliant. What a great performance and good for the whole team.
"Going out on the second circuit he was going really well. He's just good.
"The moment I first saw the horse with Paul Barber (joint-owner) we said 'wow'.
"Neptune Collonges has been improving all the time and Kauto ran a good race too, but they were beaten on the day by a better horse. It's brilliant for the whole team."
Barber's partner in Denman is the effervescent professional gambler Harry Findlay, who said: "We had to get the tactics absolutely right to beat our stablemate (Kauto Star).
"Forget about your Grand Prix and your football and your tennis. This was two stablemates. We had to do what we had to do to break the champion.
"All this about conspiracy theories and whatever, we've had to do everything to break Kauto Star's heart and that's what we've done.
"We've gone through the race so many times and we knew what we had to do. It was just brilliant.
"Just like the Hennessy. He had a lovely lead after four fences. We all knew. We knew down the back he was going to win."
Walsh admitted he knew his fate a long way out.
He said: "The best horse on the day won.
"I was struggling past the winning post on the first circuit when Sam picked it up. I just couldn't get there. Well done to them all.
"Denman has gone a good old gallop, but he was going no quicker than they did in the Tingle Creek last season. I always thought Kauto could travel but he didn't today."
Walsh had been in the unenviable position of having to choose which horse to ride and sadly for him got it wrong.
He went on: "If you get it wrong, you get it wrong. I could only ride one. I picked the wrong one and that's racing.
"Of course he (Kauto Star) could come back next year. On any given day any horse can win."
Paddy Power make Denman 7-4 favourite to retain his crown in 2009 with Kauto Star a 4-1 chance.
Kauto Star's owner Clive Smith was magnanimous in defeat.
"It's a great winner for the stable and I'm very pleased for the Denman connections," he said.
"We didn't quite run up to our best, but I'm not saying we might have done any better. Congratulations to the Denman camp.
"Ruby said the horse found the ground a bit tacky and he didn't jump so well. He couldn't get off the ground so well.
"It's an incredible game. You're up one day and down the next. I think we'll have him (Denman) in the rematch in 12 months' time. I'm fine and happy about it."