Sizing John enjoyed his moment in the spotlight as he gave trainer Jessica Harrington her first victory in the Timico Cheltenham Gold Cup with her first runner when coming home a clear-cut winner of jumping's blue riband prize.
So often in the shadow of the mighty Douvan over two miles, the seven-year-old completed the English-Irish Gold Cup double in style to dispel any stamina doubts.
Given a patient ride by Robbie Power, Sizing John kept on strongly up the hill to score by two and three-quarter lengths from the staying-on Minella Rocco (18-1).
Djakadam travelled well for most of the race and looked as though he might end Willie Mullins' hoodoo in the showpiece event, but Sizing John (7-1) pounced to lead between the final two fences.
Native River (7-2), who went to toe to toe with Champagne West for the early pace, showed plenty of guts to be beaten just a short-head in third while Djakadam - twice the runner-up - was fourth after making a costly jumping error at the second-last fence.
County Kildare-based Harrington said: "I can't believe it, it was amazing how he jumped and travelled.
"Robert said he wasn't going to go down the inside, but he did. It's absolutely fantastic, my first runner in a Gold Cup.
"He was running over two miles, but it was Robert who said he would stay and he did.
"Thanks to everyone at home, it's all down to the team. I can't believe it, I've got to get a Classic now (on the Flat)!"
She added: "I've never had a runner in the race before so to train the winner - I don't know when I'll come down to earth.
"You can tell Robert did showjumping in his youth because I don't think he missed a beat the whole way.
"I was thinking it was all going a bit too easy. I was glad that on the first circuit he put a few short ones in and he wasn't winging fences.
"When he pulled him out on the second circuit, he began jumping well. Just at the top of the hill I saw Robert give him a squeeze and he flew.
"This is the jewel in the crown, I've been watching and listening for as long as I can remember.
"He's only seven so I've got to keep him right and mind him. I've no idea what he'll do next, all I was thinking about was this race."
Owner Alan Potts said: "It's unreal, it's my dream and it's come true.
"It's our first runner in the race, the jockey's first ride and Jessie's first runner."
Power, who won the Grand National on the Gordon Elliott-trained Silver Birch in 2007, said: "Unbelievable, Jessica Harrington is a genius.
"I always said when this horse stepped up in trip he'd win.
"Everyone has done a top-class job, it means more than any winner I've ridden for Jessica.
"I was only 25 when I won the National and I'm 35 now. When you're 25 you think you can win everything, so this is very special.
"Going to the second-last, even before Djakadam's mistake, I actually thought I had Ruby covered.
"Down to the last he absolutely pinged it and then it was just a case of seeing it out, it's what every jockey dreams of and I never thought I would until we got this lad.
"I had a bad injury before Christmas and I rushed back to ride him in the Irish Gold Cup. I did everything I could to get back, I wasn't letting Davy Russell on him!"
Minella Rocco's trainer Jonjo O'Neill said: "It was his first run of the season, he has no miles on the clock and he'll improve a ton on that.
"I'm thrilled, he had a great spin round and finished as strongly as anything. He will definitely run again this season, but first let's get him home and see how he is."
Cue Card, who blew a possible £1million bonus when falling at the third-last in 2016, came down at the same fence again, while Lizzie Kelly, the first woman to ride in the race in over 30 years, only got as far as the second fence where she and Tea For Two parted company.