Cue Card won the William Hill King George VI Chase at the fourth time of asking for Colin Tizzard in a pulsating finish at Kempton.
The 9-2 looked to be booked for second as Vautour pinged two out under Ruby Walsh, but his stride began to shorten, offering Cue Card a second bite.
Jockey Paddy Brennan needed a big leap at the final fence but he got in tight, as did Vautour, and the two gave their all on the run to the line
Walsh’s mount held the advantage, but the gap closed with every stride and Cue Card just got the verdict following a photo finish of a thrilling conclusion.
The nine-year-old has been revitalised this year after surgery on a trapped epiglottis and had already won the Charlie Hall and Betfair Chase in the early exchanges of this season.
Willie Mullins' Vautour had looked all over the winner after taking over at the head of affairs on the second circuit from dual winner Silviniaco Conti, who disappointed and was pulled up.
Vautour was still on a hard rein with three furlongs to run as the rest were coming under pressure, none more so than the favourite Don Cossack, who to his credit was still in with a chance when he fell at the second-last.
Al Ferof finished third for the third year in succession, this time for Dan Skelton.
Brennan said: "It's the best feeling of my whole career. I can't take it in. I've beaten one of the best horses in training and beaten one of the best jockeys I've ever ridden against.
"My wife and son watching at home will be so proud.
"It was a tight one, the last time I got in (a photo) with Ruby it was Imperial Commander against Kauto Star, I thought I'd got there then but I hadn't. But today he said to me I'd won.
"I'm not going to lie and say there was loads there, I got to the bottom of the tank but if any man is going to get him back in that sort of form for the Gold Cup it's Colin Tizzard.
"For people that say he doesn't stay, he stayed right to the line to get there."
Tizzard, whose stable star is now on the verge of a £1million Jockey Club bonus if he can win the Gold Cup, said: "Nowadays he's a completely different horse, he might not look as if he's going very well but he has that left for the end. It's fantastic.
"My wife and son watching at home will be so proud." Paddy Brennan
"He's been a great horse for five or six seasons now. Going to the last if he'd met it on a good stride he'd have won easier."
