Right from intercepting Patrick Mahomes’ first pass of the game, Buffalo looked the better side as they moved just a game behind their big rivals in the race for the AFC play-offs top seed.
Mahomes kept the Chiefs in it with three touchdown passes, but just as they threatened yet another escapology act Bills quarterback Josh Allen took the game into his own hands and settled it with a barnstorming 26-yard touchdown run.
That makes four straight regular season wins over the Chiefs for Buffalo, who have lost three play-off meetings between the sides in the past four years.
This was a more controlled and complete performance than usual by the Bills, without Allen having to do everything by himself and a sixth successive victory takes them to nine wins and two losses.
It was also a rare convincing defeat of Kansas City – their first by more than a score since October 2021 – as they finish the weekend 9-1.
Buffalo kept Mahomes’ offence to a season-low 259 yards and scored 30 points against a Chiefs defence that had gone 30 games without conceding that many.