This was seen as Allen’s best chance yet to topple the Chiefs and send Buffalo back to the Super Bowl for the first time since losing four straight from 1991 to 1994 and, like their past two play-off meetings, there was just one score in it.

Kansas City running back Kareem Hunt opened the scoring at Arrowhead by barging into the end zone from 12 yards, before the Bills cut the deficit with a field goal.

Mahomes then fumbled a hand-off for the Chiefs’ first turnover since losing 30-21 at Buffalo on 17 November, and the Bills took advantage, with James Cook getting into the corner from six yards.

Kansas City went straight back in front when Xavier Worthy reached for the pylon after taking an 11-yard pass from Mahomes, who then scrambled into the end zone to extend the hosts’ lead.

The Bills replied with Mack Hollins making a superb catch from Allen’s deep shot for a 34-yard touchdown to make it 21-16 at half-time, before going back to their run game on their first drive of the second half, with Cook showing great athleticism to reach over the line.

Then came the first of the crucial fourth-down attempts in the fourth quarter, with Allen controversially ruled short of claiming first down on a quarterback sneak.

Five plays later, Mahomes burrowed over for a 10-yard touchdown, and Allen set up a tense finale by making big plays to Cook and Hollins, before firing a touchdown pass to Curtis Samuel.

Buffalo’s defence held Kansas City to a field goal on the next drive but they failed to regain the lead as Allen was pressured into a desperate heave which tight end Dalton Kincaid was unable to hold on to.

It meant the celebrations could begin for the Chiefs, whose tight end Travis Kelce was congratulated on victory by his girlfriend, pop superstar Taylor Swift.