Native River won a thrilling Cheltenham Gold Cup after an epic duel with Might Bite.
The 5-1 chance gave Dorset trainer Colin Tizzard his first victory in the race after some spectacular jumping under champion jockey Richard Johnson.
Favourite Might Bite (4-1), seeking an historic Cheltenham Festival treble for trainer Nicky Henderson, was a gallant runner-up, beaten by four and a half lengths.
Anibale Fly (33-1) finished third ahead of Road To Respect and Djakadam.
But the race was all about the memorable battle between last year’s third-placed horse Native River and the King George VI Chase winner Might Bite.
The pair led from the front, roared on by a sell-out 70,000 crowd, and went toe-to-toe over 22 fences and three and a quarter miles in soft ground, with none of their rivals posing a serious challenge.
Henderson was bidding to be the first trainer to win the Champion Hurdle, Champion Chase and Gold Cup at one Cheltenham Festival meeting.
And Might Bite looked a serious contender for much of the race, before the 2016 Welsh National winner Native River stormed up the hill.
Winning jockey Johnson smiled broadly after his second Gold Cup win, 18 years after his first on Looks Like Trouble.
And victory sealed a 203-1 double for Tizzard, who sidelines as a dairy farmer, after 33-1 shot Kilbricken Storm won the Albert Bartlett Novices’ Hurdle on Kilbricken Storm.
More success for teenage jockey Kennedy
Irish-trained horses, particularly the powerful stables of Gordon Elliott and Willie Mullins, have dominated the meeting.
And Elliott took the opening Triumph Hurdle with Farclas for his seventh winner of the week, and a fourth for 18-year-old jockey Jack Kennedy.
Bridget Andrews became the 13th woman to ride a Festival winner when winning aboard 33-1 shot Mohaayed for trainer Dan Skelton in the County Hurdle.
There was some sad news when Sandsend, ridden by Katie Walsh, had to be put down after suffering a leg injury during the race.
‘It means everything to me’ – reaction
Winning trainer Colin Tizzard, speaking to BBC Radio 5 live immediately after the race: “It was unreal, wasn’t it? To win the Cheltenham Gold Cup means everything to everyone’s life. Let’s not pretend it’s not.
“Richard Johnson galloped and jumped as fast as he could and the horse never let him down once. He just powered away.
“We’ve had a wonderful preparation and you think something could go wrong in the race, but it didn’t.
“The Irish have been winning everything this week but Richard gave it that sort of ride. When Might Bite came beside him, Native River just flew over the last.
“He wasn’t quite right after Cheltenham last year so we’ve stuck to the plan and it has come in.
“I never thought in my biggest dreams that I would win a Gold Cup.”
Winning jockey Richard Johnson: “The horse jumped great, he answered every question I asked. He’s so genuine and the Tizzards gave him a chance and full credit to them. You couldn’t ask for a better partner.
“I was lucky enough to win this race 18 years ago and I’m just making sure I’m enjoying this moment as much as possible.”
National Hunt jockey Charlie Poste who was co-commentator on the race: “Native River has got stamina in abundance. Brilliant jumping, he stays all day.
“It takes two to tango and what a race they’ve given us. It was a joy to watch.”