Trailing by three points entering the final frame, Cutler led the Bears (9-3) on a six-play, 59-yard drive, capped by his 7-yard TD toss to Manumaleuna with 8:39 to go, handing Chicago its fifth straight win.
Cutler completed 21-for-26 pass attempts for 234 yards and Matt Forte and Chester Taylor each rushed for touchdowns for the Bears, who ensured they would stay ahead of Green Bay in the race for the top spot of the NFC North.
Chicago also got 104 yards on seven receptions from Earl Bennett.
The Lions (2-10) went with Drew Stanton at quarterback after injuries to Matthew Stafford and Shaun Hill. Stanton gained 178 yards and hurled a TD pass to Calvin Johnson in the setback.