Cutler amassed 286 aerial yards, with his favorite target being Johnny Knox, who hauled down three receptions for 97 yards and a score.
Matt Forte picked up 59 rushing yards on 21 attempts and Marion Barber ran for touchdown as the Bears (7-3) tied Detroit for second place in the NFC North.
San Diego (4-6), meanwhile, is going in the opposite direction, losing its fifth consecutive contest while falling into the AFC West basement.
Philip Rivers was picked off twice en route to a 21-of-31 passing performance for 280 yards and two touchdowns.
Vincent Jackson compiled 165 yards and a TD on seven receptions in the Chargers' loss.