Politologue (5/4 favourite) fended off Charbel (5/2) to win the Christy 1965 Chase at Ascot.
Paul Nicholls' charge looked set to record a comfortable success when mastering the freewheeling Gold Present turning for home and going to the front on the bridle.
However, he got in close to both the second last and final fence and the eventual runner-up gained momentum, closing all the way to the line.
Sam Twiston-Davies and the leader had enough in reserve to score by half-a-length.
Sky Bet left the winner unchanged at 16/1 for the 32Red King George at Kempton on Boxing Day and 12/1 for the Ryanair Chase at Cheltenham.
Racing PR Manager Michael Shinners said: "Politilogue was very well backed today and rewarded favourite backers. It will be interesting to see which route connections take."
Politologue wins ahead of Charbel in the Christy Chase at @Ascot
— ITV Racing (@itvracing) November 24, 2018
Will we see him win the King George? pic.twitter.com/eMH7qaozKq
Nicholls was at Haydock, where he told ITV Racing: "He just frightens you to death because he travelled so well and the minute he hits the front he idles.
"It's his first run of the season, but he didn't want for fitness because he was ready. He could have done with a tow in the race a little bit longer. He was giving 7lb to the second horse. All he'll do is keep improving. The better the race, the better he is.
"I don't know about the King George. All the way through that race he showed so much pace. You just have to question whether his forte is going to be stamina or whether he's got plenty of speed. He's confusing me because he does travel and jump so well in his races.
"He will probably travel as long as you want, even over three miles. Kempton is a flat track and would probably suit him and not commit too soon on him.
"He'd turned into the straight at Kempton travelling really well. It's just if he's got that stamina over three. I just don't know."
Owner John Hales is eager to go for the King George and said: "I was more worried than I will be on Boxing Day. The pressure is on you and it would have been a total failure if he had been second and the press would have given him a bad time.
"I would have thought two-mile-five around here is similar to three miles at Kempton. They will go quicker at Kempton which he wants to do. He pulled himself to the front today.
"It (King George) is now (the plan) after that, but I've got to speak to Paul. I think we have got a great chance. I had a good bet on him for the King George on the way down as if he won today, he would be shortened.
"The dream is ask me after the King George as if he shows me he gets the three miles and does really well, then I will do everything I possibly can to persuade Paul to go to the race at Cheltenham at the end of January and let's see.
"I've won everything else I want to win and I've got the Grand National at home - there is a space waiting for the Gold Cup."
Kim Bailey, trainer of the runner-up, said: "I am delighted with him. I'm just annoyed he got it wrong at the last, but he had to go for a long one and he didn't get it and it was as simple as that.
"I long to step him up and I will step him up as three miles is where we want to go. I'm now regretting I didn't make an entry in the King George, but that is easy in hindsight.
"He is a horse that will progress over three miles. That was the furthest he has been and he has improved so much.
"We were standing in March with a horse that was going nowhere. He has had a back operation and that has made a big difference and a lot has gone on behind the scenes.
"A lot of work and schooling has gone into him to get him back. We will find somewhere and we are not in a rush. We would love to take him over to Ireland, but it would be a spring campaign not a winter one."