Trainer Willie Mullins claimed a first Irish Grand National victory as an inspired display gave 6-1 favourite Burrows Saint the win at Fairyhouse.
Isleofhopendreams (20-1) once again had to settle for second with Acapella Bourgeois (18-1) completing a remarkable clean sweep for Mullins.
The win also gave jockey Ruby Walsh his third victory at the event.
Mullins, who won his first Cheltenham Gold Cup last month, has waited 21 years for his first win in the race.
Snugsborough Benny (14-1) took fourth with 25-1 chance Bellow Mome in fifth.
Legendary trainer Mullins fell agonisingly short of claiming his first Irish Grand National last year when Isleofhopendreams missed out in a photo finish.
This year the heavily fancied Burrows Saint looked controlled throughout, with the six-year-old moving to the front with three fences remaining.
Pairofbrowneyes and Any Second Now were among those considered most likely to challenge the favourite, however both fell early while early leader Total Recall, another of Mullins' seven runners, was unable to mount a challenge.
"Ruby was very confident throughout, but I thought Johnny Burke (on Acapella Bourgeois) was too and all our riders rode the last mile fantastic," said Mullins.
"It was a tremendous result. It's just been one of those years where we have done things that we haven't done before."
BBC horse racing correspondent Cornelius Lysaght
It seems odd to think that Willie Mullins, champion jumps trainer in Ireland for the past 11 seasons, and holding a significant advantage this time, hasn't won just about everything worth winning.
But prior to this spring his story in the Irish Grand National - and in the Cheltenham Gold Cup which he won for the first time in March - has always been of near misses.
Not any more after Burrows Saint defied a relative lack of experience, plus a couple of jumping fluffs, to beat two gallant stablemates, neither of which gave up without a fight.
Burrows Saint also has a bright future, and the 2020 Aintree Grand National is now sure to be in his sights.