Watch: Patrick Mahomes, Chiefs Make Critical Mistake on Final Play of First Half

The Chiefs took a 21–10 lead into halftime in Sunday's AFC championship game against the Bengals, but the margin could have been bigger.

Bengals running back Samaje Perine took a screen pass to the house from 41 yards out to cut the Chiefs' lead to 11 points with 1:05 to play in the half. Then Chiefs quarterback Patrick Mahomes went back to work, leading the offense right down the field and giving the team another opportunity to score late in the half.

After a pass interference penalty in the end zone set Kansas City up inside the five yard line, the Chiefs offense had a decision to make.

Faced with second-and-goal from the Cincinnati two-yard line with five seconds remaining in the half, Kansas City elected to go for it with no timeouts remaining.

After Mahomes took the shotgun snap and saw that his initial targets were covered, he threw a pass out to the flat on his left to Tyreek Hill, who was stopped short of the goal line as time expired.

With no timeouts remaining, the decision to check down into the flat prevented the Chiefs from scoring any points before halftime.

Mahomes doesn't make mistakes like that very often. It'll be interesting to see if the end-of-half clock management will come back to bite the Chiefs.