In his first appearance since finishing last of eight runners at Punchestown in October, the Dermot McLoughlin-trained nine-year-old wasn't fancied ahead of the €400,000 showpiece.
However, he was in front from the first fence and held off all challengers during a brilliant ride by Ricky Doyle.
Run Wild Fred was a clear second, with Enjoy D'allen third and 9/2 favourite Latest Exhibition a creditable fourth under the welter burden of 11st 10lb.
McLoughlin said: "It's great - it went to plan. I said to Ricky 'he likes to bowl along in front and jumping is his forte, so use him up'.
"I was a bit concerned about not getting a run into him. I said turning into the straight that we'd better start shouting, because I knew he'd stay going."
"Coming here I thought we had a good chance and thankfully it's worked out."
Doyle told ITV Racing: "I could not believe it - I thought everything was too good to be true! His jumping is just out of this world, but how well he travelled and the rhythm he was in (was unbelievable).
"Turning in I could feel horses on me and I could feel him picking up. I was trying to do the maths in my head and was thinking 'did I jump the last the first time'? I was in a dream the whole way.
"He's a proper summer ground horse. I won a Midlands National on him in the same way. I was just so happy with everything that I couldn't believe it.
"This means everything to me. I love this sport and I love horses - I couldn't care if there was nothing to the winner.
"I'm over the moon."