Jockey Robbie Power led Sizing John to a first Cheltenham Gold Cup success for trainer Jessica Harrington.
Power, a Grand National winner on Silver Birch in 2007, took advantage of a mistake by Ruby Walsh on Djakadam at the second-last fence to storm home, ahead of Minella Rocco in second, with Native River third, and the Willie Mullins-trained Djakadam in fourth.
It was a second major win of 2017 for the seven-year-old, who won the Irish Gold Cup at Leopardstown in February.
"It was absolutely amazing, how he jumped," trainer Jessica Harrington said.
"Robert says he wasn't going to go round the inside, and he did. It is absolutely fantastic, and unreal.
"It is thanks to Robert who was the one who said he could stay [making the step up from two miles]."
Harrington, who has never had a runner in the race before today, is now Cheltenham's top female trainer with ten career victories at the festival.
Power says the victory surpasses his Grand National victory on Silver Birch ten years' ago.
"This is even more special - I was 25 when I won the Grand National and i am 35 now," he told ITV Racing.
"When I was 25 I thought i would win everything in racing, but when you get to 35 you don't think you will so much any more.
"The plan was to keep on the outside and keep myself out of trouble, but after I jumped the second I found myself on the inside.
"I thought I'd get shot if I got brought down here, but it all worked out perfectly well. I got a dream run round and followed Ruby most of the way.
"I have learned over the years that you are never far off if you follow that man!"
Veteran Cue Card fell with three fences to go, but trainer Colin Tizzard confirmed after the race that the 11-year-old emerged unscathed.
Photo Getty Images/Ian Walton
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