Bayern Munich restored their four-point lead at the top of the Bundesliga and left Borussia Dortmund in the bottom three with a 2-1 win over their rivals at the Allianz Arena.
Marco Reus gave Dortmund the lead in the first half, but Robert Lewandowski broke their resistance before Arjen Robben sealed victory from the penalty spot.
Dortmund's seventh defeat of the season - the same number as the whole of last season - leaves Jurgen Klopp's men in 16th place, and it could get even worse on Sunday when bottom-placed Freiburg have the chance to move above them.
In light of Saturday afternoon's results, Dortmund - regarded before the season as the only team capable of wrestling the Bundesliga title off Bayern - had slipped into the bottom three.
Rather than being a battle of the titans, it had more of an air of David versus Goliath with Dortmund scrapping for their lives while Bayern go about their normal business at the top, where they have stayed almost uninterruptedly for two-and-a-half years.
When Robben cut in characteristically and saw his shot tipped over by Roman Weidenfeller, few would have predicted anything other than a home win.
Dortmund had other ideas, though. Henrikh Mkhitaryan hit the outside of the post as Dortmund showed the force of their attack, taking the lead after half an hour.
Pierre-Emerick Aubameyang found some freedom down the right and delivered a cross for Reus to head past his national team number one Manuel Neuer, who conceded for the first time in the Bundesliga after 688 minutes.
With the job done, Dortmund summoned the troops back and pitched their tents in their own half.
Roman Weidenfeller denied Thomas Muller before Robben skipped inside of the despairing lunge from Sokratis Papastathopoulos only for his shot to deflect wide.
The pressure moved up another notch in the second half with Lewandowski denied a goal against his former club and Robben finding his usual avenue bricked up.
Shinji Kagawa swivelled on the edge of the area at the other end, shooting wide with a rare opportunity on the break.
It was otherwise a monologue, and a stroke of luck helped Bayern get their equaliser.
Neven Subotic slid to block Franck Ribery's pass, feeding Lewandowski 25 yards from goal and the Pole struck his shot into the bottom corner without any hesitation.
Subotic, a half-time replacement for Mats Hummels, was involved in the move which led to Bayern taking the lead with just five minutes left.
After losing the ball to Ribery, he tried to hold the Frenchman back. Ribery used his experience in waiting until he had entered the penalty area before falling to the ground and earning a penalty.
With Muller off the field, Robben took the honour from the spot, sending Weidenfeller the wrong way to complete the turnaround and keep Bayern four points clear at the top of the Bundesliga.