Berlin (AFP) - Bundesliga leaders Bayern Munich slumped to a 3-1 away defeat at Mainz on Saturday, handing Borussia Dortmund the chance to take top spot.
Dortmund host Eintracht Frankfurt later in the day and can go one point clear with a win, with five league matches remaining this season.
Trailing 1-0 at half-time, thanks to Sadio Mane's first goal since October, Mainz then hit back scoring three goals through Ludovic Ajorque, Leandro Barreiro and Aaron Martin.
Bayern have now won just two from seven since sacking manager Julian Nagelsmann for former Dortmund and Chelsea boss Thomas Tuchel in late March.
Bayern came into the match under heavy pressure, with the Bundesliga title the last trophy available after Wednesday's Champions League exit at the hands of Manchester City.
After beginning from the bench against City, Mane and Bayern veteran Thomas Mueller were named in the starting XI by Tuchel.
Mane had the ball in the net after 14 minutes but the effort was chalked off for offside.
Mane, who sat out Bayern's last Bundesliga match through suspension following an altercation with teammate Leroy Sane, got on the scoresheet shortly after, heading a Joao Cancelo cross past Robin Zentner for the opener after 29 minutes.
Mainz, who were coached by Tuchel between 2009 and 2014, fought back after the break, Ajorque heading in from close range after Yann Sommer failed to grasp a Lee Jae-sung shot.
A shellshocked Bayern, who had controlled the game until that point, looked disorganised and Mainz took advantage by grabbing the lead through Barreiro just eight minutes later.
Martin added another six minutes after that to seal Mainz's third straight league win over Bayern at home.
In the German capital, Marvin Ducksch struck a hat-trick as Werder Bremen deepened Hertha Berlin's woes with a 4-2 win on home coach Pal Dardai's return to the dugout.
With top scorer Niclas Fuellkrug missing through injury, strike partner Ducksch starred, scoring twice in the first half and once in the second to leave Hertha stranded in last place.
Hertha brought back Dardai, who previously saved the club from relegation in 2021, last week but the Hungarian was unable to have an immediate impact.
Cologne went 10 points clear of the relegation places with a dominant 3-1 win away at Hoffenheim.
First-half goals from Florian Kainz and Davie Selke put Cologne on course for a crucial win, with both sides adding a goal each in second-half injury time.
Wolfsburg romped to a 5-1 victory at Bochum, thanks to a double from Mattias Svanberg, along with goals from Jakub Kaminski, Patrick Wimmer and Luca Waldschmidt.
Winless in three, Bochum now sit just two points clear of the relegation spots.