Last-place Gladbach had no scoring chances against 10th-place Bremen, which took the lead 77th minute, until Bradley, at the far post, ran on to a free kick from the opposite flank and hit the ball into the net off his chest from five yards in the 79th minute.
VIDEO of Bradley's goal.
The goal was Bradley's second since joining newly promoted Gladbach last summer. Gladbach is four points deep in the relegation zone, but it now has two ties in a row after having lost its five pervious games.
Donovan's first two Bundesliga appearances since joining Bayern during the winter break on loan from the L.A. Galaxy came as a a sub in the 72nd and 77th minute. But on Saturday he replaced injured Luca Toni in the 35th minute against Hertha Berlin.
The game was scoreless when Donovan entered. Bremen's Andrey Voronin scored in the 38th and 77th minute. Miroslav Klose scored Bayern's goal in the 61st minute.
Donovan was thwarted on two scoring chances by keeper Jaroslav Drobny, who made a fine diving save on the American's header from 11 yards and blocked his shot on a breakaway.
A crowd of 74,228 crowd in Berlin's Olympiastadion witnessed Hertha's win.
Toni suffered an Achilles' tendon injury and is expected to miss next Saturday's game against Cologne. That could mean a start for Donovan.