Fields and the Bears (2-2) were in much better form coming off a brutal loss at Cleveland last week. They rang up 373 yards after being held by the Browns to 47, the ninth-lowest total in league history.
Fields looked more comfortable, completing 11 of 17 passes for 209 yards and an interception in his second consecutive start with Andy Dalton sidelined because of a bone bruise in his left knee. The No. 11 overall draft pick was sacked just once, after being taken down nine times for 67 yards while throwing for just 68 the previous week.
David Montgomery ran for 106 yards and two touchdowns before leaving with a knee injury. He scored on Chicago’s first two possessions, running it in from the 4 and 9 to make it 14-0, but hobbled off the field following a 5-yard run early in the fourth quarter.
Darnell Mooney caught five passes for a career-high 125 yards, including a 64-yarder.
Robert Quinn had a strip-sack with the Lions deep in Chicago territory. Khalil Mack added a sack and fumble recovery, and the Bears got some payback for a loss to Detroit at Soldier Field last season that capped a six-game skid.
The Lions (0-4) remained winless under coach Dan Campbell and general manager Brad Holmes and lost their eighth straight since beating the Bears.
Jared Goff was 24 of 38 for 299 yards. He hit Kalif Raymond with a 4-yard touchdown in the third quarter and 25-yarder in the fourth to make it 24-14.
The Lions had the ball on the Chicago 8 with about 4 1/2 minutes remaining. But the Bears stopped them when they opted to go for it on fourth-and-1 rather than kick a field goal.
The Bears had 200 yards in the first half and took advantage of two turnovers by Detroit after the Lions got inside the 10 in building a 14-0 lead.
They went 75 yards for a touchdown on the game’s opening possession, with Montgomery carrying six times and scoring from the 4 to cap a 12-play drive.
Detroit then got to the 8, only to have the threat end on a strange turnover. Center Frank Ragnow snapped the ball as Goff was walking toward the line, and it ricocheted off the quarterback to Chicago’s Bilal Nickols.
Fields hit Mooney with a 64-yard pass two snaps later, and Montgomery ran it in from the 9 on the first play of the second quarter to make it 14-0.
The Lions then opted to go for it on fourth down at the Chicago 5 rather than kick a field goal. And the Bears’ Alec Ogletree deflected a pass intended for D’Andre Swift in the end zone.
Detroit fumbled again inside the 10 when Quinn strip-sacked Goff on third down at the 3. Mack recovered, and the Bears took over at the 23.
Chicago bumped its lead to 21-0 early in the third when Damien Williams powered in from the 4.
Lions: Ragnow (toe) left the game in the first half. … LB Romeo Okwara (foot) was hurt in the first half.
Bears: DT Akiem Hicks (groin) left the game early in the first quarter.
Lions: Visit Minnesota on Oct. 10.
Bears: Visit Las Vegas on Oct. 10.