The New England Patriots suffered their first defeat of the season as they were beaten 37-20 by the Baltimore Ravens on Sunday.
The Patriots were 8-0 heading into the game at M&T Bank Stadium but found Ravens quarterback Lamar Jackson in inspired form.
Jackson, who completed 17 of 23 passes, threw for 163 yards and rushed for 61, racking up three total touchdowns.
The Ravens now sit top of the AFC North on 6-2, while the Patriots remain at the summit of the AFC East.
The Philadelphia Eagles made it back-to-back wins by beating the Chicago Bears 22-14 at home.
Running back Jordan Howard's 13-yard touchdown against his former team in the third quarter helped his current side to victory despite a late fightback from the Bears, who at one point trailed 19-0.
The Eagles are now 5-4 and lie second in the NFC East, while the loss sees the Bears on 3-5 and rooted to the bottom of the NFC North.
In Kansas City, the Chiefs beat the Minnesota Vikings 26-23.
The home side had to play, for the second week in a row, without injured reigning MVP quarterback Patrick Mahomes.
However, Harrison Butker scored a game-winning 44-yard field goal minutes after hitting a 54-yard field goal that levelled the game.
The Chiefs and Vikings are both now on 6-3, with the former on top of the AFC West table and the latter lying second in the NFC North.
In Pittsburgh, the Steelers moved to a 4-4 record after beating the Indianapolis Colts 26-24.
With just over a minute left in the game, Adam Vinatieri had a chance to put the Colts ahead 27-26 with a 43-yard field goal.
However, he missed and the Colts (5-3) now trail the Houston Texans (6-3) in the AFC South.
The Texans hammered the Jacksonville Jaguars 26-3 at Wembley earlier on Sunday.
Elsewhere, the Miami Dolphins beat the New York Jets 26-18, the Buffalo Bills had a strong 24-9 win over the Washington Redskins, the Carolina Panthers were 30-20 victors over the Tennessee Titans, and the Oakland Raiders overcame the Detroit Lions 31-24.
The Seattle Seahawks versus Tampa Bay Buccaneers game went to overtime, with the Seahawks prevailing 40-34, the Los Angeles Chargers beat the Green Bay Packers 26-11, while in Denver the Broncos beat the Cleveland Browns 24-19.