Augsburg secured their third win of the season with the only goal right after the restart, a powerful free kick from Jan-Ingwer Callsen-Bracker deflecting in off Gladbach's Raul Bobadilla.
Gladbach remain fourth on 30 points. Leaders Bayern Munich, on 31, travel to VfB Stuttgart on Sunday while champions Borussia Dortmund, a point behind, entertain Kaiserslautern.
Werder Bremen eased past troubled VfL Wolfsburg with a 4-1 win to move up to fifth on 29 points.
The hosts took a 20th minute lead through defender Sokratis Papastathopoulos and striker Claudio Pizarro netted on the stroke of halftime, catching the Wolfsburg defense napping for his 12th goal of the season.
Forward Markus Rosenberg added a third 10 minutes after the restart and Marko Arnautovic completed the demolition after a nice pass from Pizarro. Marcel Schaefer cut the deficit with four minutes left.
Felix Magath's Wolfsburg have now won only one of their last seven matches to drop to 14th, three points off the relegation zone.
Hoffenheim won 2-0 at Nuremberg. The hosts fell behind to a Vedad Ibisevic goal in the 39th minute and then had Timothy Chandler sent off for a rough challenge on Sejad Salihovic.
Ibisevic added another early in the second half to lift Hoffenheim up to eighth place.
Cologne crushed Freiburg 4-0 with two goals from Lukas Podolski, who took his tally to 13 this season.
On Friday, Schalke 04 beat Hertha Berlin 2-1 to go second on 31 points.