Cutler and Marshall were in tune early on, connecting for two touchdowns, and Jennings returned an interception 48 yards for a score as Chicago built a 24-14 halftime lead.
The Bears were up by 13 when New York's Brandon Jacobs ran it in from the 1 in the closing seconds of the third after Jennings got called for interference against Hakeem Nicks near the goal line. That cut it to 27-21, but Jennings made up for it in a big way when he picked off an overthrown pass by Manning intended for tight end Brandon Myers at the 12 with 1:54 left in the game.
Cutler was 24 of 36 for 262 yards after throwing for 358 against New Orleans last week. Marshall played a huge role in this one after venting over a lack of catches against the Saints, finishing with nine receptions for 87 yards. Martellus Bennett had 68 yards on six catches against his former team, while Alshon Jeffery had just one reception after going off for a franchise-record 218 yards in the previous game.
Robbie Gould kicked two field goals, including a 52-yarder in the third quarter that gave him 12 straight conversions from 50 or longer, and the Bears eased at least a few nerves, even if this win came against one of the NFL's four winless teams
The Giants came in clinging to the idea that they could claw their way back into the NFC East race because every team in the division has a losing record. It's hard to see that happening, the way they're playing.
Manning, the owner of two championship rings, completed 14 of 26 passes for 239 yards and a touchdown, but he ran his league-leading total to 15 interceptions while matching last season's number. He had passes picked off on the first two possessions, with Jennings' 48-yard TD coming on the second one.
Rueben Randle had 75 yards receiving and a touchdown for New York. Brandon Jacobs, starting for the injured David Wilson, ran for 106 yards and two scores.