Mainz and Hoffenheim remained unbeaten after six games of the Bundesliga season after sharing a goalless draw.
Freiburg were denied their first win of the season deep in stoppage time as Hoffenheim claimed a draw on Tuesday night.
Bayern Munich dropped Bundesliga points for only the second time this season, as Borussia Dortmund were defeated.
Stuttgart dropped to the bottom of the Bundesliga after losing the Baden-Wurttemberg derby with Hoffenheim 2-0.
Ivica Olic salvaged Wolfsburg a point in Hoffenheim and earned his coach Dieter Hecking some breathing room.
Bayern Munich were held to a 1-1 draw by Schalke, while Bayer Leverkusen ran out 4-2 winners against Hertha Berlin.