Nicky Henderson basked in the joy of his first totesport Cheltenham Gold Cup after Long Run belied his tender years on an epic afternoon in Gloucestershire.
The Seven Barrows handler has scooped virtually all of the major prizes in the National Hunt game, but the most prestigious race in the calendar had somehow eluded him.
But that all changed within a handful of glorious minutes as the 7-2 favourite, expertly ridden by amateur Sam Waley-Cohen, jumped impeccably to follow up his similarly accomplished success in the King George VI Chase at Kempton in January.
Indeed, the race lived up to all of its billing as, with half a mile to go, three former champions, Kauto Star, Denman and Imperial Commander, were all in a line.
But Long Run had them in his sights and he jumped to the front at the last to strike by seven lengths.
Denman ran another gallant race to finish runner-up for a second consecutive year, while Kauto Star just held off stablemate What A Friend for third.
The one major disappointment was last year's winner Imperial Commander, who was pulled up along the straight.
Nigel Twiston-Davies' disappointment will no doubt run in direct contrast to Henderson's ebullience after a trying week in which he had failed to hit the target until 40 minutes before the Gold Cup, when Bobs Worth won the Albert Bartlett.
Henderson said: "It was a great race because all the horses have run great races - there's no disputing it.
"Kauto Star was probably at his best today, but Long Run is a very good young horse.
"Sam gave him a beautiful ride. There was just a moment when I thought he needed a bit of daylight going down the hill, but he was very confident and he was very professional.
"It's sort of nice it's over, to be honest. It was a great race, that's the thing.
"All credit to Sam, this is not exactly his day job, but he never panicked.
"The big horses were all there and he had to get through them, and he did. It was a wonderful ride.
"This horse is still only six, so there is a lot to look forward to with him yet."
The young French recruit Long Run only made his British debut in December 2009, when running amok in the Feltham Chase at Kempton on Boxing Day.
He followed up at Warwick but was unable to translate that form across into last season's RSA Chase at Cheltenham.
Long Run was also considered in some quarters to be slightly disappointing on his seasonal debut in the Paddy Power Gold Cup at Cheltenham last autumn, in which he was third as the 2-1 favourite.
And even though he excelled in the King George, his two previous performances at Cheltenham led many to question his ability to handle the exacting Gloucestershire circuit.
After moving ominously well at the top of the hill, such reservations were emphatically stricken from the record as Long Run became the youngest Gold Cup winner since Mill House struck in 1963.
The winning jockey said: "He's a whole lot better than I thought he was.
"That's a very special feeling and he's a very special horse.
"I want to say thank you to everyone for believing in me and the horse.
"This is beyond my wildest dreams. I didn't think we were going to get there, but he picked up, and I think he still had a bit left.
"When he got there he saw the crowd and he wanted to stop and have a look.
"What a horse he is."
Long Run is owned by Robert Waley-Cohen, the young jockey's proud father.
Waley-Cohen snr said: "To have a runner in the Gold Cup is an honour, but to have your son riding the winner is a dream.
"He jumped the last really well and I knew they were never going to catch us after that.
"He's a gorgeous young horse."
Paul Nicholls said of his placed horses, Denman and Kauto Star: "I thought they had it between them at one stage, but Long Run was always going well just behind.
"They've run absolutely amazing races.
"Kauto travelled great and jumped great and we were always going to be more positive on him.
"I always thought Long Run was the best young horse in the race but I could not be more proud of my horses."
Sam Thomas, rider of Denman, said: "He's come back here three or four times now and not finished worse than second, but there was a much younger horse there today.
"I had a bit of a job just to get him to lay up early on as he wasn't really in love with it.
"The ground wasn't the problem, it's the speed they go on the ground, but he's done a great job to keep involved, the further he goes the more he enjoys it, he's a pleasure to ride."
Ruby Walsh said of Kauto Star: "It was a good gallop and Kauto has run an absolute cracker.
"I was just hanging on to him a little bit in the hope that we could accelerate off the bend but at 11 that acceleration is just not there.
"You can't knock him and you can't knock the winner. Fair play to Sam.
"Paul had him spot-on, he jumped and he travelled. He's been some horse but the younger brigade have landed on him today."
Sir Alex Ferguson, part-owner of What A Friend, said: "I can't think of seeing a better race than that.
"He had three great horses in front of him so we are delighted with him.
"We might look at the Scottish National for him."
Clive Smith, owner of Kauto Star, is undecided about the future of the two-time Gold Cup winner.
Smith said: "He's had a wonderful career and we'll just have to see what happens now - we'll sit down and talk about.
"There was definitely a stage when I thought he could win, especially when Ruby was taking control down the back straight.
"I thought he had every chance coming down the hill, but you've got to hand it to Long Run.
"He's obviously got a great turn of foot to come past Kauto and Denman, and he has a younger pair of legs.
"It would be easy to say retire him now, but we'll see.
"He might hate it if he was retired and he certainly ran well today."
Paddy Brennan, deflated rider of Imperial Commander, declared after the race: "He's pulled up lame."
Perhaps surprisingly, the winning connections indicated Long Run may not be quite finished for the season.
Waley-Cohen snr said: "There's very few options left, but there's Aintree (totesport Bowl) and France."
Sam Waley-Cohen continued: "The two races in France he could run in would be the French Champion Hurdle and the Grand Steeple-Chase, both at Auteuil.
"We're going to have to have a think about it as we've had to work very hard to adapt his style to British racing."
Imperial Commander, meanwhile, was later found to have burst a blood vessel.
Twiston-Davies said: "He burst a blood vessel at the top of the hill and that's why he made a mistake.
"I don't think he'll run anywhere else this season - I'd imagine it would be Haydock (Betfair Chase) again in November.
"It was a fantastic race and it was great to see the old guard at the front."