The win sees Lucien Favre's side move level on points with their French counterparts in Group C as Filip Daems' first-half penalty and a Peniel Mlapa wonder strike proved to be enough for the Foals to secure a crucial first victory in their European campaign.
Lucien Favre selected his twelfth different starting line-up this season and buoyed by the home supporters saw his charges get off to an energetic start. However, having set out their stall to hand Marseille the initiative whilst seeking out their chances on the counter, it was their final pass, often looking to release Luuk de Jong, that let them down.
Marseille almost managed to use their hosts' risky tactics against them as Loic Remy twice went close, firstly with a back post volley, which Marc-Andre ter Stegen knew little about in making his save, before heading over from corner with the young keeper stranded.
The hosts responded well though and after Juan Arango's devilish free-kick was saved on the line by Steve Mandanda, Havard Nordtveit's attempt to play the ball back into the danger area saw Charles Kabore pulled up for handball. Captain Daems stepped up to confidently open the scoring from the penalty spot and with neither side able to string their passes together it was the hosts, who went in at the break with a slender lead.
Having dominated the opening half hour Marseille sought to brush off the shock of going behind after the restart but, while Rod Fanni's header looped just past the post, were denied by some last-ditch defending from Gladbach. The Foals were allowing the French side to build up a head of steam by regularly conceding possession and won't have been happy to see de Jong substituted after the Dutchman came off second best in a goalmouth scramble.
No sign of a comeback
It didn't make much difference though as, soon after Joey Barton had twice come close to an equaliser, de Jong's replacement, Mlapa, won the ball in midfield before unleashing a devastating drive that beat Mandanda at full stretch. Just like in the first half the goal sparked Gladbach into life, but having scored from 25-yards Mlapa failed to find the net from five, while Martin Stranzl saw his effort ruled out by the offside flag as Borussia saw out the win by allowing proceedings to peter out late on.
Gladbach: ter Stegen - Jantschke (Brouwers 32'), Stranzl, Dominguez, Daems - Nordtveit, Marx - Rupp, Herrmann (Hanke 80'), Arango - de Jong (Mlapa 65')
Marseille: Mandanda - Abdallah (Cheyrou 83'), Fanni, Nkoulou, Mendes - Kabore, Barton - Amalfitano, Valbuena, J. Ayew - Remy (A. Ayew 65')
Goals: 1-0 Daems (Pen. 33'), 2-0 Mlapa (68')