Hertha Berlin cemented their place in the top three of the Bundesliga with a regulation 2-0 home victory over Mainz.
Czech midfielder Vladimir Darida put the hosts in front in the 34th minute, with former Chelsea forward Salomon Kalou adding the second nine minutes after the break to seal a sixth win from seven games in all competitions for Pal Dardai's side.
Andre Schubert's men had lost their last three games in all competitions, conceding 13 goals in the process, but they overcame Granit Xhaka's first-half dismissal as a late effort from Oscar Wendt saw off the visitors at Borussia-Park.
After Marcel Heller had given Darmstadt the lead in the 28th minute, Gladbach saw Xhaka sent off - for the third time this season - after aiming a wild kick at Peter Niemeyer off the ball.
Sandro Wagner equalised for Darmstadt midway through the second period, but Wendt's effort four minutes from time earned Gladbach the points.
