Newly crowned Bundesliga champions Bayern Munich suffered a 3-1 defeat to Mainz at the Mewa Arena on Saturday afternoon.
Jonathan Burkardt and Moussa Niakhaté put the home side ahead in the opening 30 minutes.
Robert Lewandowski pulled a goal back in the 33rd minute, but Leandro Barreiro restored Mainz's two-goal advantage in the 57th minute.
Borussia Dortmund and Bochumaa settled for a share of the spoils after playing to an entertaining 3-3 draw.
The visitors raced into a two-goal lead in the opening 10 minutes thanks to goals from Sebastian Polter and Gerrit Holtmann.
However, Erling Haaland brought Dortmund back on level terms after converting a penalty in the 18th minute and another one on 30 minutes.
Haaland went on to complete his hat-trick in the 62nd minute, but Bochum spoiled the part after Jurgen Locadia bagged an 82nd minute equaliser.
Stuttgart and Wolfsburg settled for a share of the spoils at the Mercedes Benz Arena on Saturday.
John Brooks' 13th minute strike looked to have clinched the win for the visitors until Chris Fuhrich bagged the equaliser for Stuttgart in the 89th minute.
FC Cologne kept their European hopes alive with a 4-1 victory over Augsburg at the WWK Arena.
Anthony Modeste contributed with a brace after Mark Uth and Jan Thielmann netted for the visitors, while Florian Niederlechner bagged the consolation for Augsburg.
Arminia Bielefeld struck late in the second half to earn a 1-1 draw against Hertha Berlin.
Lucas Toursart's 55th minute strike looked to have won the game for Berlin, before Joakim Nilsson snatched the equaliser in second-half stoppage time.
