Pittsburgh Steelers went 4-0 for the season as rookie wide receiver Chase Claypool ran in four touchdowns to inspire a thrilling 38-29 win over the Philadelphia Eagles.
The other unbeaten record on the line on Sunday tumbled, though, with the Las Vegas Raiders stunning the Kansas City Chiefs with a 40-32 victory.
Elsewhere, interim head coach Romeo Crennel got off to a winning start with the Houston Texans, while there was an emotional return for Alex Smith as Washington continued to struggle.
CHASE RUNS AWAY WITH IT
Pittsburgh's unblemished start – the first time they have gone 4-0 since 1979 – owes much to the burgeoning relationship between veteran quarterback Ben Roethlisberger and breakout star Claypool.
A stunning outing began when he ran into the end zone for a two-yard score after a seven-minute drive in the first quarter before Roethlisberger found Claypool for a third-down completion and a 14-7 advantage.
Claypool also scored on the Steelers' first drive of the third quarter and Roethlisberger targeted the Canadian youngster 11 times. He did so tellingly with Pittsburgh holding a slender two-point lead in the closing minutes, allowing Claypool to conclude a stellar performance that featured seven receptions, 110 receiving yards and six rushing yards.
Kansas City found themselves on the wrong end of a typically high-scoring affair against the Raiders, who had five plays of at least 40 yards and made 490 yards overall in offense.
The game was in the balance at 24-24 at half-time but Patrick Mahomes threw his first interception of 2020 in the final quarter – Josh Jacobs ultimately the beneficiary with his second touchdown.
Derek Carr threw three TDs as Las Vegas improved to 3-2.
CRENNEL GETS HOUSTON ON THE BOARD
A 0-4 start saw Houston fire Bill O'Brien and install Crennel as the oldest head coach in NFL history.
He was 73 years and 115 days old on Sunday, but perhaps felt half his age as the Texans compiled a 30-14 win over the Jacksonville Jaguars, who are now similarly 1-4.
Deshaun Watson threw two interceptions but had a solid outing overall, finding eight different catchers and completing 25 of 35 passes for 359 yards and three touchdowns.
ALLEN RETURNS BUT WASHINGTON WOES CONTINUE
Already without Dwayne Haskins, Washington's problems at quarterback were compounded when Kyle Allen took a helmet-to-helmet hit from Los Angeles Rams' Jalen Ramsey.
It meant a return for Alex Smith, making a first NFL appearance for 693 days after recovering from a career-threatening compound leg facture in 2018.
The 36-year-old was understandably rusty, getting sacked by six times as the Rams ran out 30-10 winners.
Washington have now lost four consecutive games by 14 or more points – the first such slump by a franchise since 2001.
Joe Flacco coming in for injured signal caller Sam Darnold did nothing to lift the New York Jets from their malaise as a 30-10 defeat to the Arizona Cardinals at MetLife Stadium saw them drop to 0-5.
The Cardinals' Kyler Murray passed for a career-high 380 yards and one touchdown, while also rushing for a TD of his own.
Murray completed 27 of his 37 passes, including one of 37 yards for a DeAndre Hopkins touchdown. Hopkins racked up a game-high 131 yards and five other Cardinals players broke 30 receiving yards.
Flacco was 18 of 33 for 195 yards and a touchdown, while he was sacked twice.
Week 5 scores:
Los Angeles Rams 30-10 Washington
Pittsburgh Steelers 38-29 Philadelphia Eagles
Arizona Cardinals 30-10 New York Jets
Las Vegas Raiders 40-32 Kansas City Chiefs
Carolina Panthers 23-16 Atlanta Falcons
Houston Texans 30-14 Jacksonville Jaguars
Baltimore Ravens 27-3 Cincinnati Bengals