Al Boum Photo gave trainer Willie Mullins his first victory in the Magners Cheltenham Gold Cup following a dramatic race for the showpiece event.
Leading at the second-last fence, Al Boum Photo (12-1) dug deep for jockey Paul Townend, who was also winning the Gold Cup for the first time.
Anibale Fly stayed on strongly to finish second, two and a half lengths away, with Bristol De Mai another three and three-quarter lengths back in third.
Watch Lydia Hislop's interview with Willie Mullins - Gold Cup-winning trainer
After six second places, Mullins finally broke his Gold Cup hoodoo. His three other runners - Kemboy, Bellshill and Invitation Only - failed to finish. It was later reported Invitation Only had suffered a fatal injury.
Mullins said: "I've got used to the disappointment of finishing second.
"I thought Bellshill would take a lot of beating, but Ruby (Walsh) wasn't happy with him and pulled him up early. To have three of the four runners out of the race before they came to the second-last first time round - I was depending on one.
"Every time I looked at Paul, his body language told me was very happy and the horse was relaxed.
"When he came over the last, I just looked at the winning post and thought nothing would come and get him unless he stops or runs out or something like that.
"I was here when my dad (Paddy Mullins) won with Dawn Run and I didn't get home for two days.
Winning owner Joe Donnelly on what victory means to him
"I sort of resigned myself to never winning a Gold Cup. Certain jockeys may never win the feature race of their lives, like the Grand National or the Champion Hurdle. I thought maybe I'm not going to be lucky."
He added: "It was Paul's plan to jump out and get a position and just keep jumping and getting balanced. From an early stage he got him jumping in a rhythm. Every time he needed a squeeze, the horse responded.
"Paul started off with us when he was 17. He was riding as a claimer for me and he won the Galway Hurdle for John Kiely and that really put him on the scene.
Townend reveals he is "tingling all over" after his first Gold Cup triumph
"He has just been unlucky he has been alongside Ruby. Hopefully he might be champion jockey for the second time and he is out in front. I'm sure like any jockey this will be a lifetime achievement for him."
An emotional Townend - who hit the headlines for the wrong reason with Al Boum Photo at Punchestown last season, dramatically running out when in the lead - said: "I can't believe it. It's the Gold Cup, there's only one a year and I never dreamt I'd win it.
"Like any race, when you're going well it's so simple.
"It's unbelievable and I'm privileged to be riding for Willie Mullins."
Anibale Fly ran a huge race to better this third place from 12 months ago.
Tony Martin gives his reaction to the run of Anibale Fly
His trainer Tony Martin said: "He's run a blinder, but this was the one time I didn't want Willie to win the Gold Cup!
"He is in the National again and obviously he was placed in it last year after running so well in the Gold Cup before, but he's had a hard race there.
"We'll just have to see how he is, it's only three weeks away."
Nigel Twiston-Davies had a word for those who might have written off the chance of Bristol De Mai.
He said: "The experts are the experts and I haven't got a clue why they are experts. He was the joint top-rated in the race and he got beat, so maybe they are right!
"He's been very sound this year. When he ran in this two years ago he'd had problems, but he's been fine this year.
Richard Johnson said things went wrong from the start for the gallant fourth native River
"He's just top class, not just at Haydock, anywhere - he's just finished third in the Gold Cup."
Defending champion Native River was fourth, with Presenting Percy, the 100-30 favourite, in eighth.
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