Al Boum Photo charged clear at the Cheltenham Gold Cup on Friday to belatedly give trainer Willie Mullins his first triumph in the iconic race.
Mullins celebrated his 64th Cheltenham Festival win - the most of any trainer - to finally put six second-place finishes behind him.
Last year's front two Native River and Might Bite were in the mix for long stretches, but Al Boum Photo (12-1) moved three lengths clear as he went over the last fence.
Anibale Fly dashed through to come second yet could not reel in the leader, with favourite Presenting Percy out of the picture.
Mullins told ITV Sport: "It feels great. I'm delighted for the connections, delighted for Paul [Townend, the jockey].
"It's good to get the Gold Cup finally. Three of my other four runners were out before the first circuit finished. But Al Boum Photo looked so relaxed and I knew he could jump.
"I come here every year and start afresh, but I didn't think I would have a good Cheltenham with how the winter had gone. Here we are."
He added: "I've got used to the disappointment of finishing second, so I wasn't expecting anything here."
Earlier, Triumph Hurdle favourite Sir Erec had to be put down as his serious injury cast a shadow over Pentland Hills' victory in the first race of the day.
The 11-10 shot lost a shoe and delayed the start, yet he looked to be going well until suffering a broken leg with four hurdles remaining, allowing Pentland Hills to capitalise amid muted celebrations.
"You never like to win a race when that's happened in it, but that's the reality of the sport," winning jockey Nico de Boinville said of Sir Erec.
In the Spa Novices' Hurdle, Minella Indo went off at 50-1 and pipped 4-1 favourite Commander Of Fleet to give jockey Rachael Blackmore her second win of the week.