Bristol De Mai won the Betfair Chase at Haydock by 57 lengths as Cue Card trailed in second.
The 11-10 favourite, steered home by Daryl Jacob for trainer Nigel Twiston-Davies, was almost finishing while his nearest rivals jumped the last.
Bristol De Mai will be aimed at next month's King George VI Chase. Victory at Kempton and in the Cheltenham Gold Cup would seal a £1m Jockey Club bonus.
"He's a phenomenal horse, he's a beautiful horse," said Jacob.
|Victory in numbers|
|Bristol De Mai won by 57 lengths. A length is eight feet in racing, so the win was about 137 metres, or 456 feet|
Galloping grey Bristol De Mai relished the heavy going and led from start to finish of the race over an extended three miles and one furlong.
"He has a big engine and can go faster than that," said Twiston-Davies of the victor.
Runner-up Cue Card - a three-time previous winner of this Grade One contest - was never in a position to threaten.
Earlier, there was an emphatic victory in the stayers' handicap hurdle for the Jedd O'Keeffe-trained Sam Spinner (6-1), ridden by Joe Colliver.
Owners celebrate winning double
Bristol De Mai's win completed a big-race double for owners Simon Munir and Isaac Souede, who also claimed the Christy 1965 Chase at Ascot with Top Notch.
Lil Rockerfeller (9-4) won the Coral Hurdle for Neil King, with 10-11 favourite Defi Du Seuil unplaced.
In Ireland, the Willie Mullins-trained favourite Min (1-9) scored at Gowran Park and remains around 6-1 third favourite for the Queen Mother Champion Chase at the Cheltenham Festival in March.
BBC horse racing correspondent Cornelius Lysaght
It's believed that no horse has ever won a Grade One race by Bristol De Mai's vast 57-length margin, and though he does relish extreme-soft going more than others, this was a striking performance.
He hardly put a foot wrong, and though not brilliant at the second-last, he 'put himself right' easily enough.
He'll be chasing the £1m bonus for completing Kauto Star's Haydock-King George-Cheltenham Gold Cup treble but may need a wet winter and spring.
Cue Card's jumping was maybe lacking a little fluency, but he jumped round okay this time, and ran with credit.