Mainz 05's Lee Jae-sung scored either side of the break as the hosts stunned Bundesliga leaders Bayern Munich 2-1 on Saturday to snap their unbeaten league run this season.
South Korea international Lee struck four minutes before the break after pouncing on a defensive blunder by the lacklustre visitors.
The 32-year-old then doubled the hosts' lead on the hour, turning beautifully in the box to finish a superb attacking move that left the complete Bayern defence frozen to the spot.
It was also the first league loss for Bayern coach Vincent Kompany, who last week became only the third coach in Bundesliga history to have gone without defeat in his first 13 league games in charge.
The Bavarians, missing eight players to injury including top scorer Harry Kane, pulled back a goal with Leroy Sane in the 87th.
Bayern remain in top spot on 33 points, four ahead of Bayer Leverkusen, 2-0 winners at Augsburg.
