KC’s defense had some good moments but also struggled, for the most part, slowing Buffalo’s pass offense behind Allen. Chiefs cornerback Chamarri Conner had the top highlight, intercepting Allen on fourth-and-3 in the second quarter and returning it 29 yards to set up a Gray 2-yard touchdown.

The Mahomes-Allen rivalry is now tied 4-4 (including playoffs) with just two points separating the two clubs in those meetings. Allen has the most wins by any quarterback against Mahomes, who is clearly hoping he gets another shot at the Bills this year.

The Kansas City Chiefs, defending Super Bowl champions, suffered their first loss of the NFL season on Sunday, falling 30-21 at Buffalo after winning their first nine games.While the Bills have beaten Kansas City in each of the past four NFL seasons, the Chiefs have eliminated the Bills from the playoffs in three of the past four seasons.