Lee Jae-sung scored twice as Mainz claimed a shock 2-1 win over Bundesliga leaders Bayern Munich.
Bayern went into Saturday’s contest at Mewa Arena with an unbeaten record in the league under Vincent Kompany, but that streak came to a halt.
South Korea international Lee struck four minutes before the break after pouncing on a defensive blunder by the lacklustre visitors.
Lee then doubled the hosts’ lead on the hour, turning beautifully in the box to finish a superb attacking move that left the Bayern defence frozen to the spot.
Bayern, missing eight players to injury including top scorer Harry Kane, pulled back a goal with Leroy Sane in the 87th minute.
They remain in top spot on 33 points, four ahead of Bayer Leverkusen, who were 2-0 winners at Augsburg.