Back In Focus put up a determined staying performance to give Willie Mullins his fourth winner of this year's Cheltenham Festival in the John Oaksey National Hunt Chase.
The eight-year-old, who has stamina in abundance, wore down Tofino Bay up the hill to snatch the spoils from Nina Carberry in the four-mile contest for amateur riders.
Rival d'Estruval fell at the second last when separating the two principals and it was Back In Focus (9-4 favourite) who scored for owner Graham Wylie by half a length from Tofino Bay.
Godsmejudge was 19 lengths back in third.
Highland Lodge and Tofino Bay shared the pacemaking duties until the field fled down the hill on the final circuit.
Tofino Bay was still going well when Highland Lodge cried enough while the always prominent Back In Focus was not far away with Rival d'Estruval and Buddy Bolero looking dangerous.
Tofino Bay had them all at full stretch two out and Dessie Hughes' charge seemed to have the race in his grasp when Rival d'Estruval came down.
"I know how much it means to Patrick and it means that much to me as well" - Willie Mullins sums his latest success
But the record-breaking amateur Patrick Mullins, riding for his father, had other ideas and came with a wet sail to deny Tofino Bay to the delight of favourite backers.
When asked to put into words the sensation of a Festival winner - his first over fences - Patrick Mullins said: "It's like trying to describe colour to a blind person.
"He was a little bit keen. He made one mistake down the back straight and I had to sit and let him get his breath back. He's very tough and very brave. He was brilliant."
Willie Mullins said: "I'm delighted for Patrick to break his duck over fences here.
"He galloped and stayed and I'm over the moon.
"That winner means as much as any I've had here.
"I know how much it means to Patrick and it means that much to me as well.
"It looked like Nina had stolen it, but the horse found huge reserves.
"He has an entry in the Irish National, but that will probably come too soon, so he might go to Punchestown.
"He might be another one to bear in mind for the French Champion Hurdle."
Owner Graham Wylie said: "It's great to be back. To win it is just fantastic.
"We knew he was a nice horse, but we didn't know whether he'd get four miles.
"It's like a National trial so he could be (a future National horse).
"Patrick gave him a great ride."