A missed kick by the Atlanta Falcons allowed the Kansas City Chiefs to secure the top spot in the play-offs with a 17-14 victory, which marked a club-record 10th consecutive win.
The Chiefs rallied to take the lead when quarterback Patrick Mahomes connected with wide receiver Demarcus Robinson with just under two minutes remaining.
The reigning Super Bowl champions then relied on a solid defensive effort as they forced the Falcons to attempt a field-goal, but Younghoe Koo's 39-yard attempt pushed to the right seconds before the clock ran out.
Earlier, the Cleveland Browns missed their chance to secure passage to the post-season when they fell 23-16 to the New York Jets, while the Chicago Bears dominated the Jacksonville Jaguars 41-17.
Lamar Jackson kept the Baltimore Ravens alive in the AFC with a 27-13 victory over the New York Giants, the Cincinnati Bengals fought their way back to a 37-31 triumph over the Houston Texans and the Pittsburgh Steelers mounted an even more impressive fightback to finish 28-24 against the Indianapolis Colts.
The Philadelphia Eagles set up a battle for the NFC East next week and could miss the post-season for the first time in four years after going down 37-17 to arch-rivals the Dallas Cowboys.
Washington stumbled 20-13 at home against the Carolina Panthers, quarterback Justin Herbert drove down the field late to ensure his Los Angeles Chargers finished 19-16 over the Denver Broncos and the Tennessee Titans lost 40-14 to the Green Bay Packers.
The Seattle Seahawks gritted their teeth and got it done in an immense second-half effort from Russell Wilson and the defence as the side secured the NFC West.
Wilson had 225 passing yards and two touchdowns, including a 13-yard toss with just under three minutes left that followed an 80-yard drive and saw his side finish 20-9 over the Los Angeles Rams.