The dragon wore No. 15, and a desperate fan base that has lived with the memory of four successive Super Bowl failures, the last one 30 years ago, howled every ounce of cold-blooded venom it could summon at him.

This dragon had breathed fire on their dreams twice before, but that was in Kansas City, it couldn’t happen now, wouldn’t happen now in his first road playoff game. On this night, 60 spine-tingling minutes from the AFC Championship game, all of western New York turned its lonely eyes to you, Josh Allen, to stop this fire-breathing dragon from melting the biggest NFL dreams.

It must have seemed cruel to the Bills Mafia army that was bundled up inside Highmark Stadium on Sunday night that Patrick Mahomes was born after Wide Right, was born 20 months after the last time their beloved Bills would get to play for a Lombardi Trophy, and there he was, stalking his third Super Bowl championship with the Chiefs.

It was time to slay the dragon.

Mahomes may have had Taylor Swift cheering him and Travis Kelce on but Allen had a deafening chorus that Jim Kelly and the boys of yesteryear would have recognized.

Patrick Mahomes flexes during the Chiefs’ playoff win over the Bills on Sunday.AP

Slay the damn dragon and you go to Lamar Jackson’s Baltimore for the AFC Championship game next Sunday. Slay the damn dragon and go chase history. Slay the damn dragon and give yourself a chance to check out of Heartbreak Hotel.

Patrick Mahomes (17-for-23, 215 yards, 2 TDs, 6-19 rushing) versus Josh Allen (26-for-39, 186 yards, 1 TD, 12-72-2 TDs rushing).

Heart in everyone’s throat, from Kansas City to Buffalo and every place else.

The dragon slayed the Bills.

The dragon slayed Josh Allen.

Patrick Mahomes 27, Josh Allen 24.

“I love being at Arrowhead and playing in front of that crowd, but when you’re on the road, it’s you [versus] them,” Mahomes said. “It’s you [versus] everybody in the stadium.”

Mahomes versus The World and The World lost.

“Losing sucks,” Allen would say. “Losing to them, losing to anybody at home sucks.”

This was compelling theater and high drama as two heavyweights pressed to impose their will on the night.

Two pressure-proof, weather-proof quarterbacks going toe-to-toe in the center of the ring.

Sixty minutes of ebb and flow.

Mahomes ahead. Mahomes behind. Allen ahead. Allen behind.

Bills QB Josh Allen is emotional after another playoff loss to the Chiefs.AP

“I know that’s it gonna come down to the end, just ’cause of the competitor that he is and the player that he is,” Mahomes said.

Now it was the fourth quarter.

“I went over to the defense and I told ’em, if y’all shut it down, we’ll win this football game and we’ll go to the AFC Championship game,” Mahomes said.

Mahomes, trailing 24-20, had just hit Marquez Valdes Scantling for 32 yards and Isiah Pacheco’s 4-yard TD run made it Mahomes 27, Allen 24.

And suddenly Sean McDermott made a gamble he could have regretted: direct snap to Damar Hamlin fourth-and-5 at his 30. It got 2 yards.

The football gods saved him. Mecole Hardman, first-and-goal at the 3, fumbled a catch through the end zone. After a successful McDermott challenge overruled that Hardman was down by contact at the 1, it was Allen’s ball.

Patrick Mahomes jumps for joy after the Chiefs beat the Bills on Sunday night.AP

Now there was 8:23 remaining to next week or next season.

Stefon Diggs let a bomb slip through his hands. Allen didn’t flinch. Fourth-and-3 at the 50: 10 yards to Khalil Shakir.

Now he was 26 yards from next week or next season at the two-minute warning.

He missed Shakir in the end zone. “Just couldn’t get into the throw,” Allen said.

Tyler Bass 44-yard FG to tie.

WIDE RIGHT. Heavens to Scott Norwood, WIDE RIGHT.

“I wish he wouldn’t have been put in that situation,” Allen said. “You win as a team, you lose as a team. One play doesn’t define a game.”

Mahomes had taken the opening second-half kickoff and hit Valdes-Scantling for 30 yards, scrambled for 24 more and found Travis Kelce for the 3-yard TD pass that was their 16th and broke the Tom Brady-Rob Gronkowski TD connection and made it Mahomes 20, Allen 17.

(Pan to Taylor Swift in suite celebrating with a shirtless Jason Kelce gulping a beverage of choice behind her.)

Allen found Shakir on third down with a 13-yard TD pass. Allen 24, Mahomes 20.

Patrick Mahomes and Josh Allen embrace after the game.Getty Images

“We got to make one more play and we didn’t,” Allen said.

Last one with the ball would have won in overtime. The dragon didn’t get the chance.