Dortmund have conceded three in consecutive Bundesliga home games for the first time since September 2000 and are six points off the pace. DW's Matt Ford sees serious problems at both ends which aren't being addressed.
Marc Bartra's curling effort into the bottom corner was the first goal that Bayern Munich have conceded in the Bundesliga since the return of Jupp Heynckes. And what a goal it was, yet it elicited barely even a cheer from the massed yellow and black ranks on the Südtribüne.
The damage had already been done in the previous 88 minutes in which Peter Bosz's Borussia Dortmund team had done little to correct the two major problems which have now seen them win only two of their last nine games in all competitions – and one of them was against third division Magdeburg.
Having conceded 14 goals in their last six matches, much has been said and written about Dortmund's defensive problems. Their makeshift backlines have been exposed all too frequently by long passes played by opposition defenders who, despite Bosz's insistence on a high pressing game, have been afforded too much time on the ball by Dortmund's forwards.
Excuses can be made when Harry Kane or Cristiano Ronaldo are causing problems but, with respect, questions have to asked when it's Hannover's Ihlas Bebou or Eintracht Frankfurt's Sebastian Haller getting in behind.
Against Bayern on Saturday night however, the problems were at the other end – especially in the first half. Ahead of kick-off, Bosz had referred specifically to the importance of Dortmund making the most of their opportunities – they recorded 30 shots on goal against Nicosia in midweek and yet found the net only once – and that lack of ruthlessness was on display again here.
First, Pierre-Emerick Aubameyang hesitated just long enough for the impressive Niklas Süle to slide in and make a vital last ditch block. Then Andrey Yarmolenko, so composed and clinical in front of goal earlier in the season, shot straight at Sven Ulreich when one-on-one. Shinji Kagawa was unlucky that his shot was deflected onto the outside of the post.
At the other end however, Bayern exhibited that world class quality which sets them apart in German football, provided it is harnessed correctly by the coach in question. Against Dortmund, Robert Lewandowski's instinctive movements in the box twice resulted in goals – one from the Pole himself and another when David Alaba's cross floated straight in after Lewandowski had distracted Roman Bürki with his very presence.
But the difference in class was best demonstrated by Arjen Robben's opener – a goal of three distinct stages, each executed to perfection. Thiago's inch-perfect cross into James Rodriguez, the Colombian's weighted control on the chest in a tight space and, finally, Robben's ability to take a measured step back to allow the ball to roll in just the right position for him to bend it home with a trademark left strike.
Having led the Bundesliga by five points just one month ago, Dortmund now find themselves six points behind Bayern, have been leap-frogged by RB Leipzig too and are as good as out of the Champions League.
They are ahead of local rivals Schalke on goal difference only and the Revierderby is just three weeks away. Never mind Europe, the threat is suddenly a lot closer to home.