ORCHARD PARK, N.Y. >> For all the changes the Buffalo Bills had at wide receiver and on defense this offseason, the one big constant that remained was quarterback Josh Allen.

And when the four-time defending AFC East champions needed their franchise player the most after falling behind by 14 points in their season opener against Arizona on Sunday, Allen delivered by taking matters into his own hands — and leaping legs.

Allen capped his four-touchdown outing in a 34-28 win by going airborne. Scrambling to his right from Arizona’s 6, Allen burst toward the goal line and hurdled Budda Baker before being pushed from behind by another Cardinals defender and landing hard in the end zone.

The touchdown put the Bills up 31-20 with 8 1/2 minutes left and capped a surge during which Buffalo outscored the Cardinals 28-3 spanning halftime.

“I thought it was the flyover,” left tackle Dion Dawkins said, comparing Allen’s leap to the Air Force jet that zipped over the stadium during the national anthem. “I just said, shoot, what goes up, must come down. And I hope you come down in the end zone.

“And he did. You know, that big quarterback, it’s hard to stop that, especially when you’re flying.”

Allen said his leap was a split-second decision, especially after he lowered his shoulder while bowling over linebacker Xavier Thomas on a 7-yard touchdown run just before the end of the half.