Adrian Clayborn must've thought he was the one replacing Ezekiel Elliott in the Dallas Cowboys' backfield.
Clayborn spent most of Sunday running around back there, making life miserable for Dak Prescott with one of the greatest pass-rushing performances in NFL history.
A solid player but hardly a star, Clayborn set an Atlanta record with six sacks and forced a pair of fumbles to lead the Falcons past the Cowboys 27-7, a game that showed just how much Dallas missed one of its key offensive players.
No, not Elliott, though that was certainly a blow. After three legal reprieves, the star running back finally began serving a six-game suspension for allegations of domestic abuse .
The Cowboys were also without left tackle Tyron Smith, who couldn't go because of groin and back injuries. Third-year player Chaz Green stepped into the spot -- and had a thoroughly miserable day trying to stop Clayborn.
Leaving Green grasping at air, Clayborn blew by him to force two fumbles -- one of which he recovered himself by ripping the ball away from Prescott -- and surpass the team record of five sacks in a game, held by Chuck Smith and Hall of Famer Claude Humphrey.
"You always envision it," Clayborn said. "I was finally in my groove."
He matched the second-most sacks in NFL history. Derrick Thomas, Osi Umenyiora and Fred Dean are the only other players credited with six sacks in a game, while Thomas holds the league record with seven for Kansas City against the Seahawks on Nov. 11, 1990.
Clayborn had more sacks in this contest than any other season except for his rookie year in 2011, when he had 7.5.
He came into Sunday with two sacks on the season and 22.5 over his seven-year career.
"AC went crazy today," Falcons receiver Julio Jones said.
Simply put, Green couldn't cope with Clayborn's speed.
"It just hurts because I feel I let the team down," Green said. "I've just got to get better. It's on me."
While Clayborn and the defense dominated the Elliott-less Cowboys, Matt Ryan threw a pair of short touchdown passes and reached 40,000 career passing yards in fewer games than any other quarterback in NFL history. Ryan has 40,073 yards in 151 games, surpassing the previous mark of 152 held by Drew Brees.
Ryan hooked up with Justin Hardy on a 3-yard pass for Atlanta's first offensive touchdown in the third quarter this season . Early in the fourth, Ryan put the game away for the Falcons (5-4) by tossing one to Austin Hooper for a 1-yard score.
Things started promisingly enough for the Cowboys (5-4), who jumped ahead 7-0 on Prescott's 11-yard touchdown run in the first quarter. The score was set up by Xavier Woods' interception off a deflected pass.
Atlanta took control from there, ending Dallas' three-game winning streak.
After Matt Bryant's 50-yard field goal, Tevin Coleman powered over from the 1 to give Atlanta a 10-7 halftime lead.
The third quarter was a trouble spot for the Falcons, whose only touchdown in the period had come way back in Week 2 on Desmond Trufant's fumble return. Atlanta had managed only one field goal in the third over its previous five games, a major reason the Falcons lost four of those contests.
Coleman, who took over the running duties after Devonta Freeman went out early in the game with a concussion, got the Falcons rolling on the first play of the second half with a 17-yard romp. Ryan went to Jones with a 24-yard pass on the next play, and just like that Atlanta was in Dallas territory.
On third-and-goal at the 3, Hardy slipped free in the back of the end zone and hauled in the scoring pass that pushed Atlanta's lead to 17-7.
Dallas' last hope faded away when Mike Nugent, filling in for injured kicker Dan Bailey, clanked a 38-yard field goal attempt off the upright late in the third quarter.
Atlanta marched right down the field again. Ryan went to Taylor Gabriel on a 34-yard pass before connecting with Hooper from the 1.
The Cowboys started former Pro Bowler Alfred Morris at running back, but he didn't have much of an impact beyond a 20-yard run.
Morris finished with 53 yards on 11 carries.
Rod Smith ran three times 14 yards, while Darren McFadden was thrown for a 2-yard loss on his lone carry.
Prescott chipped in with 42 yards on six carries.
Freeman was hurt on Atlanta's second offensive play. After gaining one yard on first down, he took a blow to the side of the head from Cowboys linebacker Anthony Hitchens.
Wobbly after the hit, Freeman walked off the field with the help of trainers. After a brief stint in the observation tent, he was taken to the locker room and didn't return.
Dallas linebacker Sean Lee also went out in the first quarter with a hamstring injury.
Cowboys: Return home to face the NFC East-leading Philadelphia Eagles (8-1) next Sunday night.
Falcons: Travel to Seattle to take on the Seahawks (6-3) in a Monday night game.