Bayer beat Cologne 2-1 away in the ninth round of the German championship.
Aleix Garcia put the visitors ahead in the seventh minute, and Patrik Schick scored in the 85th. Said El Mala pulled one back for the hosts in stoppage time at the end of the second half.
Bayer moved up to fifth in the standings with 16 points. Cologne, on nine points, are 15th.