Tom Brady conjured a last-gasp Houdini act to save the New England Patriots in a thrilling win over the Houston Texans on Sunday as the Atlanta Falcons preserved their unbeaten record.

With events off the field dominating a dramatic day that saw widespread player protests, Brady once again laid on a masterclass to throw for five touchdowns in a 36-33 victory at Gillette Stadium.

The crowning moment of a 378-yard passing display by the 40-year-old Brady came with the Patriots trailing 28-33 with just over two minutes remaining. 

An eight-play 75-yard drive ended with Brady hitting receiver Brandin Cooks with a 25-yard pass into the end zone for the game-winning score.

The nerve-jangling finale capped an extraordinary game which had seen sections of the Patriots crowd boo several of the team's own players after they opted to kneel during the playing of the national anthem before kick-off.

Brady had stood with his arms interlocked in solidarity with his team-mates during the solemn anthem rendition.

It was just one of several large protests by players across the league on Sunday following remarks by US President Donald Trump. Trump had enraged NFL stars and team owners on Friday by describing players who protest during the anthem as "sons of bitches" who should be fired.

Around 130 players across the league took a knee on Sunday during the anthem, easily the largest mass demonstration of its kind since former San Francisco quarterback Colin Kaepernick began the protests in 2016.

"We felt like President Trump's speech was an assault on our most cherished right --  freedom of speech," Denver star Von Miller explained after kneeling before his team's game against Buffalo. 

- Falcons soar -

The Patriots win helped New England move to 2-1 in the AFC East, putting them level with the Buffalo Bills who lead on points difference.

The Bills pulled off an upset win over the unbeaten Denver Broncos, winning 26-16. Quarterback Tyrod Taylor threw for two touchdowns and 213 yards to spark the Bills.

But it was an unhappy afternoon for Broncos quarterback Trevor Siemian, who failed to throw for any touchdowns and was twice picked off for costly interceptions.

Denver were one of seven previously unbeaten teams to taste defeat in early games on Sunday.

In Detroit, Matt Ryan threw for two touchdowns as the Atlanta Falcons won the battle of the unbeatens with a hard-fought 30-26 victory over the Lions.

Ryan, desperate to atone this season after last year's Super Bowl collapse, made 24 completions from 35 passing attempts to finish with 294 yards at Ford Field.

The win leaves Atlanta with a perfect 3-0 record at the top of the NFC South while Detroit fell to 2-1 after the loss.

Matthew Stafford finished with 264 passing yards but was crucially unable to mount a game-winning drive late in the fourth quarter as the Lions sought to overturn a four-point deficit.

The Carolina Panthers meanwhile saw their unbeaten start to the season end with an emphatic 34-13 loss to the previously winless New Orleans Saints.

Saints veteran quarterback Drew Brees shredded the vaunted Panthers defense with three touchdown passes for 220 yards.

In later games Sunday, Aaron Rodgers conjured a 27-24 overtime win for the Green Bay Packers against the winless Cincinnati Bengals at Lambeau Field.

Rodgers found receiver Geronimo Allison with a 72-yard connection to set up Mason Crosby's winning field goal.

Kansas City meanwhile preserved their unbeaten record with a 24-10 victory over the Los Angeles Chargers. The Chiefs are now 3-0 to lead the NFC West.

In Washington, Kirk Cousins passed for 365 yards and three touchdowns, running back Chris Thompson had 150 yards receiving and a touchdown, and the Washington Redskins posted a 27-10 win over the Oakland Raiders. 

Meanwhile in the day's early game at Wembley Stadium in London, Jacksonville quarterback Blake Bortles dismantled the Baltimore Ravens en route to a 44-7 win.

Bortles threw for four touchdowns as Jacksonville improved to 2-1. 

Ravens quarterback Joe Flacco meanwhile had a nightmare day, making just eight of 18 pass attempts for 28 yards with two interceptions.

Pittsburgh meanwhile have their own problems after sliding to a 23-17 overtime loss against the Chicago Bears at Soldier Field on Sunday.

The Steelers, who opted to remain in their dressing room during the national anthems before kick-off, were sunk by Jordan Howard's 19-yard walkoff touchdown.