(CNN) -- The Kansas City Chiefs beat the Green Bay Packers on Sunday in Arrowhead Stadium, ending the defending Super Bowl champions' quest for a perfect season.
The Packers, who were 13-0 this season, were defeated 19-14 by the 5-8 Chiefs.
Despite the loss -- the Packers' first in 20 games -- Green Bay remains firmly atop the NFC standings. The Chiefs are in last place in the AFC West.
Kansas City executives on Monday fired head coach Todd Haley after the team lost four of its previous five games. Sunday's win was the first under interim head coach Romeo Crennel. Crennel was previously the team's defensive coordinator.
Also Sunday, the Indianapolis Colts ended their winless season with their first victory, beating the Tennessee Titans 27-13. The Colts, previously 0-13, have been struggling without star quarterback Peyton Manning as he recovers from neck surgery.