Carlingford Lough gave Tony McCoy his first victory in the Hennessy Gold Cup just a day after he announced his impending retirement in a thrilling race for the Leopardstown showpiece.
Just 35 minutes after winning the previous contest on Sort It Out, McCoy treated racegoers to a memorable triumph, returning to thunderous applause.
Carlingford Lough (4-1), owned by McCoy's boss JP McManus and trained by John Kiely, had to be galvanised by the 19-time jockey champion after making a mistake at the second-last fence.
The nine-year-old responded in game fashion and got the better of Foxrock on the run-in to win by three-quarters of a length. Last year's Cheltenham Gold Cup hero Lord Windermere was third.
McCoy said: "You can't fight fate and it was obviously meant to be the way things happened.
"Fair play to John Kiely. Every day I've been on this horse he's produced the goods. He's done a brilliant job, couldn't be better.
"JP's (McManus) family are here and my family are here. It's brilliant. It's what's meant to be.
"It's amazing the people here at Leopardstown today. I have to be careful I don't get too emotional, it's not good for the image."
Carlingford Lough was halved in price to 8-1 from 16s for the Betfred Gold Cup with Paddy Power, and cut to 10-1 by RaceBets.
Kiely was quick to pay tribute to McCoy and also to JT McNamara, who was left paralysed by a fall at Cheltenham in 2013.
"The sad thing about it is, I won't get to steer him around for much longer, but there you go" - Tony McCoy on Carlingford Lough
He said: "That was brilliant and my thanks go to everyone, especially John Thomas (McNamara) who broke him, started him and gave him a proper attitude as to how to race.
"It was a great finish and it was special to have AP - he gave him a peach of a ride, didn't he? He's a hell of a fella - we'd have him again!
"It will depend on what Frank (Berry, racing manager) and Mr McManus say now with regards to his next target."
As McCoy warmly embraced Ted Walsh, trainer of the second horse home Foxrock, the latter quipped "It's a pity he didn't retire yesterday!"
McCoy added: "Everything went well, he jumped well other than the fourth- or fifth-last, I didn't really get much of a look at it.
"Fair play to John Kiely, he had him 100 per cent. He has had him 100 per cent for so many of the days I've been lucky enough to ride him.
"All the credit should go to John Kiely, I just steered him around. The sad thing about it is, I won't get to steer him around for much longer, but there you go.
"John is a fantastic man - every day I wanted this horse to produce the goods, John has had him 100 per cent. It's easy to do my job, I'd hate to be trying to do what John Kiely is doing.
"I might just get to steer him around on Gold Cup day at Cheltenham, which is probably the most important day of the whole jumping year and, on today's performance, he's got a live chance.
"He didn't really perform great there last year, but he just didn't get into a rhythm. He feels in great shape and look, it's a very open Gold Cup and he's definitely going to go there with a chance, hopefully."