Champagne Fever, trained by Willie Mullins and ridden by Ruby Walsh, won the William Hill Supreme Novices' Hurdle, the first race on day one of the Cheltenham Festival.
Last season's Champion Bumper winner doubled up with a game display under Ruby Walsh to strike for Irish trainer Willie Mullins.
My Tent Or Yours appeared to be going much the better at the final flight, but Champagne Fever kept finding more and held the favourite by half a length.
Jezki was third, a further two and a quarter lengths away, as the big meeting finally got going after a 35-minute delay caused by the Arctic weather.
Walsh said: "He jumped like a stag and travelled really well."
As expected, Champagne Fever took the field along from his stablemate Un Atout, with My Tent Or Yours third.
There was little change in the order as the 12-strong line-up bunched up at the top of the hill.
My Tent Or Yours looked as though he could take the leader whenever his rider Tony McCoy wanted, but Walsh and Champagne Fever had other ideas and ran out worthy winners.
Walsh said: "It's magic - he just came alive the last fortnight.
"I didn't ride him work last week but I was watching him work at the Curragh with Willie and we both kind of looked at each other. It was scintillating.
"Patrick (Mullins, trainer's son) has always maintained he was a two-miler and an out-and-out galloper - he was dead right.
"He wasn't doing a whole lot in front, but I knew AP (McCoy) was coming to me as I could feel the crowd revving up.
"But, in fairness, when AP got to him, he stuck his head down and away he went again."
Mullins said: "It was a very brave performance from the horse to lead like that and jump like that.
"Ruby said he heard Tony McCoy coming up behind him and the horse just took off with him.
"He knew he'd lots of horse. Ruby was trying to steady it and ride a tactical race - he obviously got it spot-on.
"It was fantastic to watch him coming up the hill."