Borussia Dortmund slipped back to the bottom of the Bundesliga despite picking up a point in their goalless draw at Bayer Leverkusen.
Mainz pulled away from immediate relegation danger in the Bundesliga with a 5-0 drubbing of Paderborn.
Leicester City have held talks with Mainz about a possible deal for forward Shinji Okazaki, according to Sky sources.
Mainz have made their second signing of the winter by taking Christian Clemens on loan until the end of next season.
Bayern Munich suffered their biggest scare of the Bundesliga season so far in a 2-1 win at Mainz.
Bayern Munich managed to extend their unbeaten Bundesliga record with a come from behind 2-1 win at Mainz.
Live only on