Bayern Munich slumped to a 1-0 home loss to Werder Bremen on Sunday courtesy of a Mitchell Weiser goal to stay seven points adrift of leaders Bayer Leverkusen in the Bundesliga title race.
It was Werder's first victory in Munich since 2008 and Bayern's second league loss of the campaign.
The result leaves Bayern on 41 points in second place with a game in hand. Leverkusen are on 48 following their last-gasp 3-2 win over RB Leipzig on Saturday.
The hosts, who face Union Berlin in their postponed league game on Wednesday, struggled throughout to break down a disciplined Werder backline.
The visitors also put the ball in the net with a 25th-minute quick break only for Justin Njinmah's effort to be disallowed for a foul at the start of the move.
Former Bayern player Weiser did it better in the 59th minute, charging into the box, then pulling back to shake off his marker and fire an unstoppable shot past keeper Manuel Neuer.
The host then poured forward but had no clear plan with top scorer Harry Kane missing the target with a close range header in the 72nd.
Werder keeper Michael Zetterer then palmed a Leroy Sane shot wide in the 79th before tipping the ball away from Kane's head a little later as the visitors held on to their big league win.