Wolfsburg reduced Bayern Munich's deficit at the top of the Bundesliga to 11 points after a 2-1 win over Cologne.
Bayern Munich continued their unbeaten start to the Bundesliga season with a 2-0 win over Freiburg on Tuesday night.
Mainz's winless run in the Bundesliga stretched to eight games as they came away from Cologne with just a point.
Schalke suffered their first home defeat under Roberto Di Matteo as Cologne claimed a precious 2-1 win.
Bayern Munich remain seven points clear at the top of the Bundesliga after a 1-0 home win over Bayer Leverkusen.
Augsburg moved into contention for a Champions League berth next season with a 2-1 win at Cologne.
Live only on