The Kansas City Chiefs knocked the Bills out of the play-offs in four of the past five years but with the Chiefs missing out this season, along with AFC rivals Baltimore and Cincinnati, this was meant to be Buffalo’s year.

Despite being the AFC’s sixth seed, Buffalo were still narrow favourites against a team that had won 13 of their previous 14 games and a defence that led the league for sacks – yet it was turnovers that hurt the Bills.

Allen had not turned the ball over in any of his six previous play-off games but had two fumbles in three plays either side of half-time, both resulting in Denver field goals.

That added to the Broncos’ lead after touchdowns by Frank Crum and Lil’Jordan Humphrey cancelled out Mecole Hardman’s opener for Buffalo.

Allen had also thrown 200 passes without an interception before being picked off in the third quarter here, yet the 29-year-old regrouped to help Buffalo put up 17 unanswered points thanks to Keon Coleman and Dalton Kincaid touchdowns in the fourth quarter.

After a Marvin Mims score put Denver back in front with 55 seconds left, Allen led the Bills into position for 41-year-old Matt Prater to level matters with a last-gasp field goal

However, even though the Buffalo defence got a stop on the first possession of overtime, Allen gave up his fifth turnover of the day as Denver cornerback Ja’Quan McMillian claimed an interception in a contested catch with Brandin Cooks.

Wil Lutz’s fourth field goal ensured Allen has lost all three of his overtime games in the post-season, and all seven overall in his career.

Allen and boss Sean McDermott also have the most play-off wins by a quarterback and head coach without reaching a Super Bowl (eight).

Last week’s victory at Jacksonville ensured Buffalo become just the fourth team to claim a play-off win in six straight seasons. The other three each won three Super Bowls – but the wait for this Bills team goes on.