Hoffenheim extended their unbeaten start to the season to seven games by picking up a point in a 1-1 draw at Hamburg.
Hamburg picked up their first Bundesliga win to pile misery on Borussia Dortmund, while Bayern Munich thrashed Hannover.
Hoffenheim moved up to second in the Bundesliga on Saturday with a 2-1 win over Schalke.
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.
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