Bundesliga leaders Bayern Munich continued their miserable week with a 3-1 loss at Thomas Tuchel's former side Mainz, opening the door for Borussia Dortmund to go top later on Saturday.
Mainz went 10 unbeaten after Yann Sommer's mistake allowed Ludovic Ajorque to cancel out Sadio Mané's opener and Leandro Barreiro completed the home comeback on 73 minutes, with Aaron Martin adding the gloss.
Bayern were held by Hoffenheim last weekend before going out of the Champions League in midweek at the hands of Manchester City as their season threatens to implode.
Dortmund - also previously coached by Tuchel - host Eintracht Frankfurt in the late game hoping to win and take over at the top by a point with five games to play.
Pal Dardai's third stunt in charge of bottom side Hertha Berlin got off to a terrible start, Marvin Ducksch netting a hat-trick in a 4-2 away win for Werder Bremen. Fourth-bottom Bochum lost 5-1 at home to Wolfsburg. Cologne won 3-1 at Hoffenheim, who are not yet safe, as all aways sides but Bayern made hay.
