In an entertaining game riddled with unforced errors, Borussia Dortmund ran out 3-2 winners thanks to Roman Burki and Raphael Guerreiro's late winner.
Lacklustre Bayern Munich dropped points for a third time in four Bundesliga games, stuttering to a 2-2 draw against relegation-threatened Mainz.
The Bayern Munich defender was subbed off in the 17th minute after suffering a left knee strain.
Bayern failed to bounce back from their Champions League exit as they are held at home by Mainz.
Bayern Munich could only extend their lead at the top of the Bundesliga to nine points after a 2-2 draw with Mainz at the Allianz Arena.