Hoffenheim dealt a surprise 1-0 defeat to FC Bayern Munich which saw the reigning Bundesliga champions stop just short of a 21-game unbeaten run.
Andrej Kramaric scored the only goal for Hoffenheim as the team advanced within a point of second-placed RB Leipzig, although the surprise league challengers have a game in hand.
Hoffenheim, whose whose 29-year-old coach Julian Nagelsmann is the youngest in the German top flight, has keeper Oliver Baumann to thank for as he turned in an inspired display to keep Hoffenheim unbeaten at home this season.
Kramaric shot wide early on, but still managed to give the hosts a deserved lead in the 21st minute with a powerful half-volley past Sven Ulreich.
But even as Hoffenheim dominated the first half, Bayern came close to levelling right before the break when striker Robert Lewandowski saw his effort hit the crossbar.
Then it was all Baumann after the break as he denied Lewandowski twice with match-winning saves, while Franck Ribery also went close as Bayern tried in vain for an equaliser.
The German champions lost only for the second time this season, although they would remain on top of the table with a strong 13-points lead. However, second-placed Leipzig will be able to trim it a little as they travel to Mainz later today.