Clan Des Obeaux made it back-to-back wins in the King George VI Chase with a dominant victory at Kempton.
Sam Twiston-Davies' mount came to the front of the field with two fences left and the 11-2 chance went well clear to win by 21 lengths.
It gives trainer Paul Nicholls a record-extending 11th win in the prestigious Boxing Day race.
The 5-4 favourite Cyrname, also from the Nicholls yard, was a distant second and never looked entirely comfortable.
But the seven-year-old winner, who is part-owned by former Manchester United manager Sir Alex Ferguson, looked the fresher and jumped superbly.
This was a particularly sweet victory for Twiston-Davies, who took the ride after Harry Cobden opted to ride Cyrname, and after Twiston-Davies was replaced by Cobden as number one jockey for Nicholls last year.
Clan Des Obeaux's only start this season saw him finish second at Down Royal in November - the same month that Cyrname inflicted Altior's first career defeat over fences. And that win may have taken more out of him than originally thought.
Although Cyrname took the lead at Kempton with over a circuit to go - and was still just about in front rounding the home turn - the eventual winner was travelling the better and showed his class.
Irish challenger Footpad was third, but the big disappointment was the Colin Tizzard-trained Lostintranslation, who seemed to be struggling to keep tabs early on and was ultimately pulled up by Robbie Power, having briefly looked like he might play a part at one stage.
'A tough call'
"It's nice to have a one-two and it's nice for Sam to ride a Grade One winner," said Nicholls. "I said all along it was a tough call for Harry. I couldn't really advise him what to do."
The trainer added: "I've always said he's a better horse this year, as he's a year older and stronger. If he keeps going forward it could put him in the Gold Cup picture.
"The key is to be really fresh - it wouldn't be the worst decision to go straight to Cheltenham with him."
He said he would try for another King George VI victory next year. "We've got to go for 12 now, haven't we? There's no reason why both horses won't be back next year."
Clan Des Obeaux is co-owned by Sir Alex with Paul Barber and Ged Mason. Nicholls said: "To win for my landlord Paul Barber, in his colours, and for Ged, who sponsors my yard, and Sir Alex, who has already been on the phone, is fantastic."
Earlier at Kempton, talented mare Epatante showed her class to win the Christmas Hurdle.
The JP McManus-owned five-year-old had disappointed when hot favourite for the mares' novices' hurdle at last season's Cheltenham Festival, but is back to form this season.
The 2-1 joint favourite won by five lengths from Silver Streak, with Ballyandy third, and gave trainer Nicky Henderson a record ninth win in the race.
BBC horse racing correspondent Cornelius Lysaght
Despite his rock solid credentials from 2018, Clan Des Obeaux was almost forgotten in the build-up this year as we majored on Cyrname, and was consequently allowed to go off at what were, in retrospect, spectacularly long odds before pulverising the opposition.
Although his stamina didn't seem to last the slightly longer Gold Cup distance at Cheltenham in March, Paul Nicholls is convinced an older, stronger Clan may be a big contender now.
To many, Cyrname looked to run out of juice over this longer distance, but Nicholls was more inclined to the theory that he simply wasn't at his best.