Cologne have left Paderborn last in the German Bundesliga with a 3-0 victory in a meeting of two struggling promoted sides.
Simon Terodde gave Cologne a ninth-minute lead on Sunday - confirmed after a lengthy video review ruled out a possible offside by teammate Sebastian Bornauw.
Louis Schaub headed in just before the hour and Bornauw headed in from a corner five minutes from time to complete a comfortable victory for the home side.
Cologne's second win of the season moves them to 15th on seven points, while Paderborn are still without a win and have lost seven of their first eight games in the top flight.
Mainz, who lost 1-0 at Fortuna Dusseldorf on Saturday, now drop into the bottom two, level on six points with Augsburg.
Schalke could meanwhile go top of the table with a win in the later kick-off at Hoffenheim.
Australian Associated Press