Many Clouds won the 2015 Grand National to give jockey Leighton Aspell his second consecutive victory in the race.
Champion jockey AP McCoy was denied a fairytale Aintree farewell, finishing fifth on favourite Shutthefrontdoor.
Aspell, who won in 2014 aboard Pineau De Re, steered his 25-1 shot to the front three fences from home and then held off the challenge of Saint Are to win by a length and three-quarters.
Monbeg Dude finished third and Alvarado came in fourth.
Aspell, 38, becomes the first jockey since Brian Fletcher on Red Rum in 1973 and 1974 to win back-to-back Nationals, while it was a third success for 79-year-old owner Trevor Hemmings, who has previously won with Hedgehunter and Ballabriggs.
|Comeback king Aspell|
|Leighton Aspell announced his retirement from racing in 2007, but returned to the sport in April 2009. He now becomes only the third jockey to win consecutive Nationals in the post-War era, after Bryan Marshall and Brian Fletcher.|
Aspell said: "It was wonderful and we will certainly celebrate tonight. I asked some big questions, but he dug deep.
"We really refreshed and recharged his battery and I tried to conserve energy. He is all heart. All season, he has had hard races. Win lose or draw, that's the best ride I have had in the National. I just hoped his battery life lasted out and it did."
McCoy appeared well placed in the latter stages, but Shutthefrontdoor tired badly from the elbow.
"I thought from the third-last fence I was running on empty," McCoy said.
"I will miss riding horses and races like that. I thought for a long way he could win. It was my last National but was a very enjoyable one."
|BBC racing correspondent Cornelius Lysaght|
|"Many Clouds again proved himself an outstanding staying chaser, not only seeing off 38 rivals in fine style but doing it while conceding weight to all but one of them, and in a fast time.|
|"The days when if a horse had more than 11 stone on its back you could put a line through its chances are well and truly over; though a decent sized slice of luck is still required, the race is no longer quite as much the lottery it once was."|
The Northern Irishman had said he would retire immediately if he had won, but the 40-year-old could now race on until the Sandown meeting at the end of April.
Winning trainer Oliver Sherwood was in tears after his decision to run Many Clouds was vindicated.
Many Clouds becomes the youngest winner of the National since Bindaree in 2002 and at 11st 9lb, the heaviest winner since Red Rum.
He also won £561,300 for Hemmings out of a total prize fund of £1m.
|More National frustration for McCoy|
|AP McCoy has been Champion Jockey in all of the 19 seasons he has been professional, but has only ever won the Grand National once, in 2010 aboard Don't Push It.|
About 72,000 spectators turned out on a sunny day at Aintree to watch the 168th running of the National.
McCoy had been strongly backed in the lead-up to the race - with more money wagered on this National than any other horse race - and bookmakers had feared a £50m pay-out if he had claimed his second victory over the 30 National fences.
Nina Carberry, the only female jockey in the race, finished 16th on First Lieutenant.
Balthazar King, one of the favourites, had a heavy fall at the Canal Turn and was taken to University of Liverpool Equine Hospital (Leahurst) for further assessment.
Top six: 1. Many Clouds (25-1) 2. Saint Are (25-1) 3. Monbeg Dude (40-1) 4. Alvarado (20-1) 5. Shutthefrontdoor (6-1 fav) 6. Royale Knight (25-1).
Nineteen of 39 starters finished - click here for the full finishing order.