Colin Tizzard’s ‘dream horse’ Lostintranslation, ridden by Robbie Power, beat 5/4 co-favourite Bristol De Mai in a thrilling Betfair Chase at Haydock Park.
Nigel Twiston-Davies’ grey, who had never previously lost a race any of his four races at his beloved Haydock, went down by a length and a half with Cheltenham Festival winner Frodon back in third.
"We've seen two sides of him today," said winning trainer Colin Tizzard to Racing Post.
"He travelled beautifully and jumped immaculately but after the second-last I thought 'this is not put to bed yet' and he had to stay. I think we outstayed Bristol De Mai and we saw another side to this horse. He's a fantastic creature.
"You don't know what he's going to find, do you? It's all right Robbie riding a waiting race but we didn't know he was going to find all that and he did in the end, he kept going all the way to the line and he looked a thorough stayer.
"It was only two years ago that Bristol De Mai beat Cue Card 57 lengths and he beat everything out of sight, so this is definitely his track so to beat him today is a feather in our horse's cap."
Power added: "That was fantastic. It was no secret how much we thought of him but today was D-Day, he was stepping into the big boys' league and they don't come much bigger than Bristol De Mai round Haydock.
"We were going to find out plenty today about his Gold Cup credentials and I think the horse has done the talking, he's answered what we thought of him."
But the jockey blamed himself for making things harder than he needed to and said: "It was my own fault turning it, I forgot how many gears he has and I should have just waited a bit longer but I got into a battle with a dour stayer too soon. To be fair to the horse he's dug deep and showed that he really does stay well."
The Ladbrokes King George VI Chase and Magners Cheltenham Gold Cup – after a possible prep race – beckon, with a £1 million bonus on offer if he can land both showpiece events.
Tizzard has won both those races in recent seasons with Cue Card, Thistlecrack and Native River yet reckons none of that trio is better over fences than Lostintranslation.
"I don't know if we've had one jump better than him," the trainer said. "He was immaculate at his fences, he was long and he makes the right shape. He's a lovely horse and we've got to make sure we look after him because they don't come along very often.
"He's got the pace and he can jump, we just need to make sure we get him on top form for those two or three races to come."
Power likened the winner to the horse on whom he won the 2017 Gold Cup and said: "Sizing John was very good, they don't come much better than him, but Lostintranslation has a lot of similarities to him. He has a great cruising speed and he jumps so well – they are the two main attributes you need in a Gold Cup contender and he has both."
Nigel Twiston-Davies felt fitness contributed to Bristol De Mai's defeat and said: "He ran an absolute blinder and probably just needed the race whereas the winner didn't.
"He looked like he was going to win at the second-last but didn't get home, and the good ground was against us. He's been superb here and it's no disgrace. He'll be better for the run but having not won this, we probably won't go to Kempton now."
Bryony Frost was 25 lengths further away in third on Frodon and said: "He's run his heart out like he always does. He jumped brilliantly against two good horses. In Grade 1s, three miles might just be stretching him slightly and over a shorter distance he can use his jumping better."
Check www.racingpost.com/racecards/ for full results & racecards.