The New One repelled the persistent challenges of Rock On Ruby and Diakali in a thrilling climax to the Doom Bar Aintree Hurdle.
Sent off the 4-9 favourite to gain compensation for a luckless run in the Champion Hurdle at Cheltenham, The New One moved up ominously at the top of the home straight in the hands of Sam Twiston-Davies, son of trainer Nigel.
Rock On Ruby put up a brave effort, however, while Diakali came from further back in the hands of Tony McCoy.
The New One looked to be holding both at bay as he raced towards the stands side, but as the line approached, his two challengers on the other side of the track were bridging the gap and the trio passed the post almost as one.
The photo-finish showed The New One had prevailed by a head, with Rock On Ruby just second ahead of Diakali.
Sam Twiston-Davies said: "He was hit and miss, jumping wise. I didn't quite get into the same rhythm as I did in the Champion Hurdle.
"I was surprised to see two (horses) on my inside at the line.
"He probably had a hard enough race (at Cheltenham) which took off some sparkle, but you can't underestimate how good a performance that was."
The New One was badly hampered by the fatal fall of Our Conor in the Champion Hurdle before flying up the Cheltenham hill to finish third behind Jezki and My Tent Or Yours.
Having been narrowly denied by Zarkandar in this two-and-a-half-mile test a year ago, he was unsurprisingly long odds-on to get back on the winning trail, but it was harder work than many expected.
Harry Fry's Rock On Ruby, winner of the Champion Hurdle in 2012 and runner-up behind Hurricane Fly a year later, was returning to the smaller obstacles after failing to live up to expectations over fences in the Arkle Trophy.
He clearly relished the change of discipline as he ran right up to his best to push the Twiston-Davies runner all the way.
The Willie Mullins-trained Diakali ran a fine race to finish fourth under top-weight in the County Hurdle at Cheltenham and also performed admirably on this return to Grade One level, finishing just a nose behind Rock On Ruby.
Nigel Twiston-Davies said: "He's the best horse we've ever had. Everyone looks for a horse like this and we've got one.
"It was a race we should have won, it wasn't that awful thing at Cheltenham when we hoped we would win.
"Everything is laid out for that (next season's Champion Hurdle).
"That's it for the season, and we'll come back early next year and see which way we go."
Fry confirmed Rock On Ruby will now remain over hurdles.
The Dorset handler said: "I'm thrilled to bits with him. He puts his heart on the line and he tries.
"On his day, he's a very good hurdler and that's what we'll stick to (hurdles).
"Noel (Fehily) has got off him and said we've got to train him for the two-mile race (Champion Hurdle) next year.
"Good ground is key to him and, on his day, he's a fantastic horse."
Mullins said of Diakali: "It was a good run. He has improved, and when he learns to settle better he'll improve again.
"He'll go to Punchestown for something now."