Goals: 1-0 Brosinski (pen. 45')
Red card: Donati (71')
Mainz started the brighter of the two sides, with Alexandru Maxim heading narrowly past the post inside 15 minutes. Cologne responded in kind, but Milos Jojic was unable to pick out the unmarked Simon Zoller following a driving run from former Mainz favourite Jhon Cordoba. Sehrou Guirassy blew the game's best opening in the 36th minute, and paid the price as Daniel Brosinski fired Mainz ahead from the penalty spot after Konstantin Raush was adjudged - with the help of Video Assist - to have fouled Pablo De Blasis.
Mainz sat back after the restart, keen to protect their slender advantage. When they did venture forward, a deflected Maxim cross almost produced the second goal, but Jean-Philippe Gbamin was unable to apply the telling touch. Cologne threatened with a set-piece of their own as Rausch whipped a direct free-kick narrowly wide of the upright. Giulio Donati's foul on Leonardo Bittencourt and subsequent red card gave Cologne a glimmer of hope with 19 minutes of normal time remaining, but it was not to be for the Bundesliga's bottom club.