Cheltenham Festival regular Buena Vista (20-1) recorded a fantastic repeat win in the Pertemps Final when leading from pillar to post.
Competing at his seventh successive Festival, David Pipe’s 10-year-old led his rivals a merry dance.
Given a brilliant ride by young Conor O’Farrell, he defied a 5lb higher mark than 12 months ago.
Paul Carberry made stealthy headway on Son Amix but he could get no closer after the last, eventually going down by four lengths.
Sivota closed late to finish third, another head away, while top weight Knockara Beau was fourth.
O’Farrell said: “I’m speechless. I just can’t thank Mr Pipe and the owners enough to give me the chance.
“I was just a passenger on him. He knows his way round here better than anyone.”
Pipe added: ``He's been fantastic for his owners and the late Jean Broadhurst, for my dad and myself.
“He’s not been bad for the young jockeys, either. Hadden Frost claiming 3lb won on him last year and Conor O’Farrell this time was claiming 5lb.
“Conor’s given him a superb ride. We went through the video of last year’s race and we talked him through it this morning and he’s gone out and done it.
“I just wondered if he could keep going. I thought he might get caught but he kept on going well.
“His Cheltenham record is superb, but like last year the ground has dried out which is a big factor with him.”
O'Farrell had last month fallen off Arrayan at Taunton with the race at his mercy, but he praised the Pipe family for keeping faith with him.
“I’ve never felt as low in my life after that and I wanted the ground to swallow me up but the Pipes were great about it and they just said that these things happen,” he added.
“This will have done my confidence the world of good and to win on my first ride at the Festival is just amazing.”
Trainer Tom Cooper said of Son Amix: ``We came here very confident we would be in the money - that is how it has turned out, but I thought he was a certainty coming down the hill.
“He travelled well and jumped great, and we are still happy he has run a good race.
“We have just run into a course specialist.
“I’d imagine he will go to Punchestown, and we will also look at Fairyhouse before that.”
Willie Mullins said of third home Sivota: “He finished off his race really well, that is his trademark.
“You would have to be delighted as the drying ground was not in his favour.
“We will look at Punchestown, but obviously the ground would be a worry there as well.”