The Gordon Elliott-trained Outlander (11-1) won the feature race on the third day of the Leopardstown Christmas Festival, the Grade One Lexus Chase.
Don Poli (12-1) was second and Djakadam (5-4 Fav) finished third.
The winner, who was unbeaten in three previous visits to the Foxrock track, received a patient ride from 17-year-old jockey Jack Kennedy and was in the rear for most of the three-mile trip.
Approaching the final fence, three Gigginstown House Stud-owned runners were in a line, with Bryan Cooper's chosen mount Valseur Lido ahead of Outlander and Don Poli.
However, Valseur Lido's stamina gave way and while Ruby Walsh conjured a late run out of Djakadam, who stayed on well after being outpaced at a crucial point in the race, it was only good enough for third place as last year's winner Don Poli stuck on for second to give trainer Elliott a one-two.
Elliott had intended to run Outlander in the King George VI Chase at Kempton on St Stephen’s Day, but made a late switch when Thistlecrack, the eventual winner, was announced as a runner.
It proved an inspired move as he produced a career-best effort on what was his fourth start of the season since leaving Willie Mullins.
Gordon Elliott's Outlander produces a storming finish to win the Grade 1 #Leopardstown Lexus Chase pic.twitter.com/BP3exXUpo5
— RTÉ Sport (@RTEsport) December 28, 2016
Second behind Djakadam in the John Durkan at Punchestown, he improved for the three-mile trip and provided the winning owners with a third successive victory in the Lexus after Road To Riches in 2014 and Don Poli last season.
Elliott was just as pleased with Don Poli, who was beaten just two and a quarter lengths, after having previously shown no enthusiasm at all on his first run for the yard at Down Royal.
Djakadam was another head back in third.
Others to run better than their finishing positions might suggest were More Of That and Smashing, who both showed up well for long periods.
"Outlander was our main hope because the way Don Poli ran last time, he wouldn't have won a point-to-point,” a jubilant Kennedy said afterwards.
"But we've done a lot of hunting with him (Don Poli) and it's worked.
"To win these races is great. He's improving all the time, his last run was a career-best and he improved again.
"It was great for Jack, that's his 100th winner as a jockey and his first Grade One.
"He's a big part of the team at home and he's my man so I'm trying to bring him along so I'm delighted for him.
"David (Mullins) gave Don Poli a great ride as well.
"It's just a great day all round."
Gordon Elliott toasts 17-year-old Jack Kennedy after he gave Outlander an expert steer in the #Leopardstown Lexus Chase #RTEracing pic.twitter.com/ybLlBA34YH
— RTÉ Sport (@RTEsport) December 28, 2016
