Carlys Quest, ridden by Keith Mercer, romped home to a shock victory in the Stayers Hurdle at Punchestown.
The 25-1 chance breezed past his rivals three out and was never troubled, with Kadoun nine lengths back in second.
Winning trainer Ferdy Murphy was also responsible for the third-placed Basilea Star, who was also a 25-1 shot.
Popular mare Solerina led for much of the race but faded badly on the second circuit while the well-fancied Emotional Moment was pulled up.
Our Ben, who had been the subject of a big gamble just before the race, unshipped jockey Ruby Walsh at the end of the first circuit.
Murphy admitted he was surprised as anyone to see Carlys Quest in the winner's enclosure.
"We just came here expecting to be fourth or fifth and pick up a few euros and have some fun with the owners, but this was totally unexpected," said the Irish trainer, who is based in the north of England.
War of Attrition got back to winning ways in the Swordlestown Cup Novice Chase.
The Mouse Morris-trained six-year-old, who had disappointed in the Arkle Trophy at the Cheltenham Festival and was second weeks later at Aintree, came from being well behind at the last to overhaul Watson Lake.
Along with Carlys Quest, there was another British-trained Grade One winner but it came from an unexpected source when United claimed the Colm McEvoy Auctioneers Champion Four Year Old Hurdle.
The Lucy Wadham-trained filly ridden by Leighton Aspell, pulled clear after the second last and coasted home.
Odds-on favourite Akilak, trained by Howard Johnson in England, was third.
Ballymore Properties Stayers Hurdle (Grade One)
Punchestown, 3m
1 Carlys Quest (K Mercer) 25-1
2 Kadoun (AP McCoy) 14-1
3 Basilea Star (G Lee) 25-1
Nine ran.
Swordlestown Cup Novice Chase (Grade One)
Punchestown, 2m
1 War of Attrition (C O'Dwyer) 3-1
2 Watson Lake (P Carberry) 7-4f
3 Strike Back (R Power) 10-1
Twenty ran. Dist: 1l, 20l.
Colm McEvoy Auctioneers Champion Four Year Old Hurdle (Grade One)
Punchestown, 2m
1 United (L Aspell) 6-1
2 Strangely Brown (R Walsh) 7-2
3 Akilak (G Lee) 8-13f
Seven ran. Dist: 12l, ½l.