Kansas City held on after Younghoe Koo missed a potential game-tying field goal with seconds remaining.
The battle for the AFC's No. 1 seed was a two-team race between the Chiefs and Pittsburgh Steelers for much of the season. After 12 weeks, the Steelers held an 11-0 record, and Kansas City sat one game back at 10-1.
However, Pittsburgh proceeded to lose to the Washington Football Team, Buffalo Bills and Cincinnati Bengals to fall to 11-3 while the Chiefs improved to 13-1 with wins over the Denver Broncos, Miami Dolphins and New Orleans Saints.
With the win, no AFC team can catch the Chiefs, who have earned the conference's No. 1 seed for the second time in three seasons.
Presumptive NFL MVP Patrick Mahomes leads the defending Super Bowl champions, who will be the favorites to hoist the Lombardi Trophy once again in February. They suffered a Week 5 hiccup against the Las Vegas Raiders in a 40-32 loss but have otherwise dominated while posting the league's top scoring offense.
Kansas City has been phenomenal ever since Mahomes officially took over as the team's starting quarterback in 2018.
The 2018 Chiefs went 12-4, earned the No. 1 seed and reached the AFC Championship Game but lost to the eventual Super Bowl champion New England Patriots.
Last year's Chiefs also went 12-4 and outscored a trio of postseason opponents 117-75 en route to the franchise's first Super Bowl win in 50 years.
Kansas City will host the Los Angeles Chargers in Week 17 to close out the regular season before hosting an AFC Divisional Round game on either January 16 or 17 against a to-be-determined opponent.