Buffalo's defense played a significant role in the win, limiting the Bears' league-leading rushing offense to 80 yards and 2.8 yards per carry. No Chicago drive was longer than 53 yards, and after a game-opening touchdown drive by the Bears, the Bills limited Chicago to two field goals on the drives that started in Bears territory.
Fields threw for 119 yards and a touchdown. But he ran for a season-low 11 yards after joining Michael Vick and Lamar Jackson as the only QBs with 1,000 yards rushing last week, with the Bills containing him and keeping him in the pocket.
As for the Bears' defense, they managed to make a few plays, and they caused three turnovers against one of the best offenses in football. With the amount of injury that Chicago's defense has, this is still pretty remarkable.