Rank outsider Lisnagar Oscar pulled off a shock win to claim the Stayers' Hurdle on Day 3 of the Cheltenham Festival.
Ridden by Adam Wedge, who claimed his first Festival winner, Lisnagar Oscar finished two lengths clear of Ronald Pump, with Bacardys third.
Hot favourite Paisley Park, who has been such a dominant force in the division, including in this race last year, never threatened to get in a serious blow.
Last year's winner Frodon and Bryony Frost finished well down the field.
Wedge said: "Unbelievable, it's fantastic. The little horse has tried his heart out. I couldn't believe it when I hit the front, I was just praying he'd keep galloping - he fought like a little lion up that hill."
Trainer Rebecca Curtis added: "He [Wedge] is brilliant, such a solid jockey, so I'm delighted for him as it's his first Festival win."
Samcro edged a titanic tussle with Melon to prevail in a photo-finish at the end of a memorable edition of the Marsh Novices' Chase.
The pair flashed past the line almost inseparable, but Samcro rallied when he had to and won by barely a whisker - officially a nose - with admirable veteran Faugheen just a length further behind in third, as Irish horses dominated the finish.
It was redemption for Samcro, who lost his form so alarmingly at times following his 2018 Ballymore Novices' Hurdle victory but has now doubled his Festival tally.
After home hope Itchy Feet unseated his rider with a circuit still to run, the Irish contingent took over - and it was Gordon Elliott's Samcro and Davy Russell who proved just the best, from Willie Mullins' brave runner-up Melon.
Russell was full of praise for Samcro's winning performance, and admitted he was far from sure they had got the better of Patrick Mullins on Melon - until the photo-finish result was announced.
"It was perfect," he said.
"He missed the second last, winged the last and went ahead to win.
"Patrick's horse battled very gamely - I thought he'd just chinned me.
"He actually headed me - but to be fair to my horse, he was so game. He's as brave as a lion, and he got back up in the last stride."
Elliott added: "He's the forgotten horse, but he's one of the favourites in the yard.
"We love him, he's brilliant."
Red-hot rider Barry Geraghty added a fourth winner of the week, as the Elliott-trained Sire Du Berlais repeated last year's success in the Pertemps Final, beating stablemate The Storyteller .
Min came good for Willie Mullins and Paul Townend in the Ryanair Chase.
Twice a runner-up in previous visits to the Cheltenham Festival, the Rich Ricci-owned nine-year-old enjoyed himself in front and just had enough in the tank to hold the strong late challenge of the Harry Whittington-trained Saint Calvados.
A Plus Tard had to settle for third.
Mullins said: "He's been a super horse for us and it's great he's had his day here.
"We used the wrong tactics on him in the Champion Chase last year and it didn't work out. He likes to be up there, Paul let him do that and here he is again at the top table."