The home side went ahead as early as the sixth minute when Juanan put the ball into his own goal.
Dani Schahin almost halved the deficit for Dusseldorf just minutes later when his attempt from a narrow angle from distance went wide.
Dusseldorf eventually made it 2-1 five minutes into the second half from the penalty spot.
De Jong was adjudged to have handled the ball inside the Monchengladbach area, and Schahin made no mistake from 12 yards.
The visitors pressed on for an equaliser for the remainder of the second half but could have conceded the third goal on 78 minutes had Herrmann's right-footed shot from close range not come off the crossbar.