Aurora's Encore was the surprise winner of the Grand National, coming from nowhere to take victory by a clear eight lengths.
The 66-1 shot left his closest rivals trailing, taking the final fence to fly past Cappa Bleu, who snatched second from Teaforthree, with Oscar Time coming in fourth.
The 11-year-old, who was runner-up in last year's race, was ridden to victory by Scotsman Ryan Mania in the jockey's first Grand National ride.
"There are no words to describe it," said Mania, who becomes the first Scot to win for almost 50 years.
"I got a dream ride round, I couldn't believe my luck. I couldn't fault the horse. I had a choice of two but he was second on this course last year so I thought I better stay loyal to him. He loved every second of it. He was just class."
Teaforthree had led the field for much of the final stages of the race, but was left for dead by the outsider over the final stretch.
The upset left punters heavily out of pocket, with the favourite, Seabass, finishing thirteenth.
Bookmakers wiped their brows as a surge of last-minute bets on the favourite came to nothing.
Winning trainer Sue Smith said: "I knew he'd stay the trip and that the ground was in his favour. I knew the ground was right for him and hoped everything else was.
"He stayed down the middle and had a bit of luck in running. He didn't have a lot of weight and that helped, too. He's such a grand little horse, you can ride him anyway you like.
"I just feel sorry for the previous owners, who were wonderful and sold him because of ill health."
Her husband, the former Olympic showjumper Harvey Smith, added: "You don't win a big 'un every day. We bought him out of Doncaster sales, broke him, made him, that's what we did. We're over the moon."
All the runners came back from the 4.5 mile, 30-fence steeplechase safe and sound, and no horses died, though two horses were put down in the previous two days' racing at Aintree.
Watching the race, England rugby union fullback Ben Foden said: "The bookies have just had a field day!"