A first Bundesliga goal from Dutch international Nigel de Jong handed Bayern Munich their first ever defeat at the Allianz Arena as SV Hamburg secured a late 2-1 win on Saturday.
Hamburg's Nigel de Jong had every reason to celebrate
Bayern had won all 11 league matches at their new home this season but Hamburg became the first team to end that streak, in the process closing the gap on the league leaders to eight points.
Werder Bremen are also eight points behind but just above Hamburg in second after missing the chance to close the gap following a 1-1 draw with Bayer Leverkusen.
Substitute Mehmet Scholl looked to have stolen a point for Bayern with an 83rd minute equalizer but de Jong's 89th minute header, his first ever Bundesliga goal, helped Hamburg register their first victory in Munich since April 1982.
Bayern's Roy Makaay must have felt like crying
"We are the more experienced team yet we concede a goal like that," fumed Bayern goalkeeper Oliver Kahn. "We had the draw which would have been fine but we wanted more. The team needs to understand that we are playing for the German title here not some local championship."
It was Hamburg's second victory over Bayern this season having won 2-0 in September.
For Bayern the defeat was untimely with a crucial Champions League showdown at AC Milan to come on Wednesday.
Milan have a slight edge after scoring a priceless away goal in the 1-1 first leg stalemate in Munich.
"We were too passive and not aggressive enough," said Bayern coach Felix Magath. "We have a big game against Milan coming up but that is no excuse."
Hamburg's Dutch Rafael van der Vaart (right) and Munich's Martin Demichelis on Saturday
Kahn was missing from the first match with Milan through a thigh injury and his return against Hamburg was far from smooth.
Predicting a cross from Cote D'Ivoire international Guy Demel, Kahn dived accross the penalty area but Demel curled the ball straight in for a 16th minute lead.
Scholl looked to have saved Bayern seven minutes from time but some slack marking from French defender Valerien Ismael allowed de Jong, a recent recruit from Ajax, to steal a winner.
"Ismael is bigger than me but that didn't matter," said de Jong. "I was desperate to get in front and it was great to score such an important goal."
Bremen still behind
Bremen meanwhile were left to rue not capitalizing on the rare slip from Bayern after their draw with Leverkusen.
Torsten Frings, one of Germany's stars ridiculed for the 4-1 thrashing by Italy in midweek, scored a penalty after three minutes to put Bremen in the box seat.
Leverkusen's Paul Freier (right) struggles for the ball with Bremen's Tim Borowski
But Dimitar Berbatov equalized on 41 minutes to deny Bremen the spoils and keep them eight points adrift of Bayern.
"It was great to see Bayern lose," said Bremen midfielder Tim Borowski. "It is just a shame we could not take all the points ourselves."
Bremen face Italian champions Juventus in their last 16 Champions League match on Tuesday holding a 3-2 cushion from the first leg in Germany.
As it stands Bayern, Bremen and Hamburg occupy the three allocated Champions League slots but Schalke 04 remain in the hunt courtesy of a 2-1 win at Hannover.
Schalke are fourth just two points behind Hamburg and Bremen.
Podolski saves the day
At the opposite end of the table promising striker Lukas Podolski gave Germany coach Jürgen Klinsmann a timely reminder of his striking talents scoring twice in FC Cologne's 4-2 win at Hertha Berlin.
Podolski had just four goals to his name this season so the brace will boost his confidence ahead of this summer's World Cup.
"Criticism is just part of football but I know what I can do and I think I showed that today," he said.
But despite the win Cologne remain bottom of the 18-strong Bundesliga, five points from safety.
On Sunday, Eintracht Frankfurt and VfL Wolfsburg tied 1-1 while Borussia Mönchengladbach beat Arminia Bielefeld 2-0.