Defending Bundesliga champion Bayern Munich fell, 3-1, at home to Borussia Dortmund, which opened its lead over Bayern by 16 points and is 12 points ahead of second-place Bayer Leverkusen.
"I think Dortmund will be champions, and rightly so," said Bayern's director of sport Christian Nerlinger. "We now have a different target, we have to go for second place now with everything we've got, and it won't be easy. It's a dangerous situation, which the players mustn't underestimate."
Dortmund, which last won the title in 2002, had also beaten Bayern in the first meeting this season.