Young attacking duo accounted for all three goals as hosts repeated their first round success with a victory over the leaders
Amid a first-half chess match, Marco Reus scored into an empty net to put the hosts ahead on 14 minutes. Patrick Herrmann made it 2-0 shortly before half-time, and completed his brace on 71 minutes. Bastian Schweinsteiger, in his first competitive game since early November, pulled a goal back in the 76th minute, but it was too little, too late for the visitors.
The game was tightly played in the opening stages, but as in his team's Bundesliga opener in August, Neuer was guilty of giving a clear chance to the hosts. Off his line, the goalkeeper passed the ball directly to Marco Reus, who collected and fired home from distance.
After going ahead, the hosts dug deep and greatly limited their visitors' chances: a well-placed Mario Gomez header on the quarter hour mark was Bayern's only clear opportunity of the half, and Marc-Andre ter Stegen did extremely well to parry it wide.
Gladbach looked dangerous on the break, and doubled their advantage four minutes before half-time as Mike Hanke, who on another occasion fired narrowly wide, slotted a brilliant through ball to Patrick Herrmann, who coolly finished when one-on-one with Neuer.
The visitors had no spark at the start of the second half, and Gladbach continued to punish the increasingly exposed Bayern. Roman Neustadter failed to complete a pass in a two-on-one counter-attacking situation, but Gladbach nonetheless were very rarely put under pressure. Philipp Lahm played a clever 1-2 with Toni Kroos, but the defender was denied a shot on goal as a last-ditch challenge resulted in a corner.
With 19 minutes left to play, Herrmann put the result to rest as he latched onto an inch-perfect through ball from Reus, rounded Neuer and made it 3-0. Bastian Schweinsteiger pulled one back on 76 minutes after a chaotic stint in the Gladbach penalty area, but his effort was no more than a consolation goal.
Bayern fought to the very end, but - Schweinsteiger's goal aside - were foiled by a resolute defence that was without the suspended Dante. Things went from bad to worse for Bayern late in the game when Daniel van Buyten hobbled off the pitch with what was later confirmed to be a suspected metatarsal fracture.
The result sees Gladbach climb to second in the Bundesliga table, just a single point behind leaders Bayern.