Espoir D'Allen produced a coming-of-age performance to claim a brilliant victory in the Unibet Champion Hurdle at Cheltenham.
A field of 10 runners went to post for the two-mile showpiece and much of the pre-race chat focused on dual winner Buveur D'Air being taken on by Irish mares Apple's Jade and Laurina.
The Gordon Elliott-trained Apple's Jade was the marginal favourite at 7/4 and challenged last year's runner-up Melon for the lead throughout, after Buveur D'Air provoked gasps from the grandstands as he crashed out in the early stages.
However, it was clear some way from home that she was in trouble and as she dropped away racing down the hill, Melon remained in front, with his stablemate Laurina travelling strongly in his slipstream.
But all the while Mark Walsh was biding his time aboard 16/1 shot Espoir D'Allen - who had won each of his three previous starts this season for trainer Gavin Cromwell - and he shot clear from the home turn to seal a hugely-impressive victory by 15 lengths.
Melon boxed on to finish second again, with 80/1 shot Silver Streak in third and Laurina fourth.
Buveur D'Air - bidding to become just the sixth horse in history to win the Champion Hurdle three times - appeared none the worse for his mishap and actually finished upsides the winner crossing the line.
Sky Bet make Espoir D'Allen 5/1 for the 2020 Champion and clipped Klassical Dream to 9/1 given the time was slightly quicker of the pair.
Cromwell said: "I'm just lost for words. It's brilliant, unbelievable. He's been winning Grade Threes this year, so to win this is fantastic."
Like Buveur D'Air, Espoir D'Allen runs in the colours of owner JP McManus, and Cromwell said: "I'm just lost for words. It's brilliant, unbelievable.
"He's been winning Grade Threes this year, so to win this is fantastic.
"I'm shell-shocked to win anyway, but to win like that - I'm just lost for words.
"When Buveur D'Air fell, we nearly got brought down. It's unbelievable, I'm completely lost for words."
Walsh said: "For a five-year-old to do that against what we thought was one of the best Champion Hurdle fields for the past few years is unbelievable.
"I was behind Barry (Geraghty, on Buveur D'Air) when he fell and luckily I wasn't in his way. I just travelled everywhere.
"I was delighted when the rain came this morning because he goes so well in it.
"I was hopeful. I was riding for a place to be honest, but from the third-last Ruby (Walsh, on Laurina) missed it. He just took me to the second-last and was in front plenty soon enough.
"I heard a horse coming and only realised after the last it was a loose horse.
"For a five-year-old to do that is very good."