The eight-year-old became the first Scottish-trained victor of the Aintree spectacular since Rubstic struck gold in 1979 after producing a tremendous display under an ice-cool Derek Fox.
The 24-year-old was riding in the world's most famous race for the first time at Aintree on Saturday but revealed he had only watched it back once.
Despite jumping into Blaklion at the second-last fence, the 14-1 shot was spring-heeled at the final obstacle of the extended four-and-a-quarter-mile test.
Cause of Causes, under amateur Jamie Codd, managed to hold off the fast charging Saint Are, runner-up in 2015, whilst the favourite Blaklion was fourth giving the oldest jockey in the race, 41-year-old Noel Fehily, his first finish in the top four in 15 rides.
Fox, who took over as stable jockey at Russell's yard following the retirement of Peter Buchanan, had been in the saddle for One For Arthur's other two wins this season, with the pair impressing in the Classic Chase at Warwick in January.
'It's been an absolutely unbelievable day, ' she told ITV after the race.
Belinda explained the name, saying: "When we bought Arthur three years ago, both our partners were playing a lot of golf. What a fantastic day we had, it's just incredible", said Russell.
"I just can't believe we've won the Grand National - it's fantastic".
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For winning jockey Fox, the win was all the more remarkable given he was injured on the 9 March and has battled from a broken wrist and collarbone to be able to ride.
Fox, who like last year's victor David Mullins was having his first ride in the race, nearly missed this glorious moment. He just jumped so well, even though he was a long way back...he was unbelievable.
"I just can't believe we've won the Grand National - it's fantastic", said Thomson. I thought we might have got to the front a wee bit early and he might get lonely but he galloped all the way to the line.
"There's a nice connection there with Rubstic and I'm very proud for Scotland, but most of all, I'm proud for everyone here". If you had said to me an hour before the race you can take him home now as the ground is too fast I would have put him in the lorry.
I can't believe it.
"I'm just delighted for Derek - he's a big part of our set up".
His father, Michael, rode the 1959 victor and son, Tom has a great chance aboard one of the favourites, the David Pipe trained Vieux Lion Rouge.