The temperature was -7C – nothing compared to the -20C for the Chiefs’ home win on Saturday – and the Bills caught the Steelers cold with three early touchdowns.
Allen produced scoring strikes to tight ends Dawson Knox and Dalton Kincaid in the first quarter, before running it in from 52 yards in the second – the longest run of his career.
Pittsburgh rallied with a Diontae Johnson touchdown shortly before half-time, before the two teams exchanged field goals in the third quarter.
And, although Calvin Austin’s touchdown cut the score to 24-17 in the fourth quarter, Buffalo hit straight back as Khalil Shakir did well after the catch to get into the end zone.
That made it three touchdown passes for Allen and secured the Bills’ sixth straight win since the start of December.