The Buffalo Bills avenged their defeat in last season's American Conference title game on Sunday with a convincing 38-20 NFL victory over the Chiefs in Kansas City.
Buffalo quarterback Josh Allen out-dueled counterpart Patrick Mahomes in a game that included a weather delay of more than an hour, torching the vaunted Chiefs offense for 315 yards and three touchdown passes.
Allen also rushed for 62 yards and a TD as Mahomes delivered one of his worst NFL performances.
He threw two interceptions, the second -- off the hands of Tyreek Hill -- was returned 26 yards for a third quarter touchdown that swelled the Bills' lead to 31-13.
Mahomes also gave up a fumble late in the fourth quarter that extinguished all hopes of an unlikely Chiefs rally.
The defeat dropped the Chiefs to 2-3, the first time since 2015 that they have been below .500.
To make matters worse, Chiefs running back Clyde Edwards-Helaire departed the game with a right knee injury in the third quarter.
With the Chiefs languishing in last place in the AFC West division, Buffalo improved to 4-1 with a their fourth straight victory to solidify their hold on the top spot in the AFC East.
The Tampa Bay Buccaneers, who beat the Chiefs in last season's Super Bowl, also improved to 4-1 with the help of another outstanding performance from quarterback Tom Brady and a record-setting day for receiver Antonio Brown.
There was no letdown for the Super Bowl champion Bucs as they returned home after Brady's emotional win against his old team, New England, in Massachusetts last week.
Brady completed 30-of-41 passes for 411 yards and five touchdowns in a 45-17 victory over the Miami Dolphins, despite injuring his right thumb early in the contest.
Two of those scoring passes were to Brown, who became the fastest player in NFL history to reach 900 receptions when he made his first catch on Sunday, off a 10-yard first-quarter toss from Brady.
Brown, 33, reached the mark in his 143rd NFL game to beat Hall of Fame receiver Marvin Harrison, who did it over 149 games in a 13-season career with the Indianapolis Colts.
"It's pretty amazing," Brady said of Brown's feat.
"I've played with some great quarterbacks," said Brown, an 11th-year pro. "(Ben) Roethlisberger. Tom Brady. It's a blessing."
Mike Evans also caught two touchdown passes for the Bucs, who trailed the Dolphins 10-7 in the first quarter before Brown and Brady heated up.
On a third and three yards play from their own 37-yard line, Brown beat Pro Bowl cornerback Xavien Howard up the middle, caught a short pass from Brady and raced for a 62-yard touchdown.
In the second quarter Tampa Bay capped a 77-yard drive with a four-yard touchdown pass from Brady to Brown in the end zone.
Elsewhere, Matt Ryan completed 33-of-45 passes for 342 yards and two touchdowns to spark the Atlanta Falcons over the New York Jets 27-20 at Tottenham Hotspur Stadium in London.
Greg Joseph kicked a 54-yard field goal on the final play to give Minnesota a 19-17 home victory over winless Detroit.
The Patriots bounced back from their loss to the Bucs as Nick Folk kicked a 21-yard field goal with 15 seconds remaining to give New England a 25-22 victory at Houston.
In Cincinnati, Green Bay's Aaron Rodgers threw for 344 yards and two touchdowns in the Packers' 25-22 over-time triumph over the Bengals.
It wasn't decided until after five consecutive missed field goals starting with 2:12 to play in the fourth quarter, Mason Crosby finally connecting on a 49-yarder after three misses to win for Green Bay.
Bengals quarterback Joe Burrow was taken to hospital as a precaution after the game with a possible throat contusion.
Burrow, who took a hard hit early, completed the game, throwing two touchdowns and two interceptions.
- Dallas thump hurting Giants -
It was a bruising day for the New York Giants, who were beaten 44-20 by the Dallas Cowboys and saw star running back Saquon Barkley depart on a cart in the first quarter with an ankle injury.
Giants quarterback Daniel Jones took a helmet-to-helmet hit from Jabril Cox and after struggling to stand up left the game with what was later confirmed as a concussion, and wide receiver Kenny Golladay was ruled out with a knee injury after halftime.
Elsewhere, the Arizona Cardinals maintained the league's only unbeaten record with a 17-10 victory over the San Francisco 49ers and the Chargers ended the Cleveland Browns' three-game winning streak with a 47-42 victory in a shoot-out in Los Angeles.