Mainz moved out of the relegation zone after defeating Koln in a five-goal thriller on Sunday evening.
Jean-Paul Boëtius gave the visitors the lead on 11 minutes, but they were pegged back after Ondrej Duda and Ellyes Skhiri put Koln ahead.
Karim Onisiwo restored parity for Mainz on 65 minutes, before Leandro Barreiro netted the winning goal in second-half stoppage time.
The moves Mainz out of the drop zone and into 14th spot, while Koln have dropped into the relegation zone due to their inferior goal difference.
Bottom-of-the-table Schalke ended a 13-game winless run in the Bundesliga with a 1-0 triumph over Augsburg on Sunday afternoon.
Suat Serdar's goal in the fourth minute was enough to secure maxium points for the home side.
The win did nothing to change their position as Schalke remain bottom of the table, 12 points adrift of the play-off spot.
Augsburg, meanwhile, remain in 11th spot ahead of next week's clash against Arminia.
