The winner, not without his supporters (11-1 to 8-1), raced just behind the pace for much of the journey, but responded to pressure to take the lead after the last.
From there he responded to pressure to deny the outsider of Willie Mullins’ two runners, Shaneshill, by half a length, with More Of That eight lengths away in third, just three parts of a length in front of No More Heroes.
“That was unbelievable,” said Twiston-Davies. “He’s done all his winning on heavy ground but I had a nagging feeling that, because he’s small, better ground might suit him - and I think it has.
“Funnily enough, he hasn’t put a foot wrong since he fell here back in November (at the Open meeting).
“It’s horrible. We don’t like falls, but it has been the making of him.
“Ryan rode him beautifully. He should have been claiming three pounds but he wasn’t.
“What a good ride - I’m delighted for him.
“The boys in the yard do all the work so we try and keep all the rides split between them.
“Ryan is very patient in a race and very good over a fence - I usually let his riding do the talking.
“Let’s hope Blaklion keeps on improving. He’s not as big as Young Hustler (who won this race for Twiston-Davies in 1993) or Imperial Commander (won the Gold Cup in 2010) but you can’t argue with what he has done today.
“I hope he makes up into a Gold Cup horse. I was inconsolable last night as I really thought The New One would win (the Champion Hurdle) but this has made up for it. I got a bit excited at the end of this race but that’s Cheltenham - we all desperately want to win.”
It was the biggest win in the career of conditional jockey Hatch, who has formed a successful partnership with the horse.
“I’ve now won a couple of Grade Twos on the horse and now a Grade One, so he’s been massive to my career, and Nigel was very ballsy in putting me up,” said Hatch, who won the Kim Muir Amateur Riders’ Race on Same Difference in 2013.
“It’s great to ride one against the pros and further my career,” he added. “I have to say a massive thank you to Nigel - we get on great and I slot in when Sam (Twiston-Davies) is not available.”
Shaneshill, who never figured as a leading fancy despite having produced two of his best performances at this meeting, gave everything but came up shy once more. Runner-up in Silver Concorde’s Bumper and Douvan’s Supreme Novices’ Hurdle, he had to settle for the role of bridesmaid for the third consecutive Festival.
More Of That, whose jumping lacked fluency, was found to have broken a blood vessel, though there was much worse news for connections of No More Heroes, who sustained a career-ending injury and was brought away in the horse ambulance.
Gigginstown House Stud manager Eddie O’Leary confirmed: “No More Heroes suffered a career-ending injury – he severed a tendon. We’re not sure when it happened, but possibly at the third-last. He’s with the vets now and is stable. He won’t run again but we’ll do our best to save him.