Dortmund manager, Thomas Tuchel is certain the 5-1 thrashing his men suffered at the hands of Bayern, made them better and shaped their season.
Bayern surged to a seven point after the win, but Dortmund has been exceptional since the defeat, closing the gap to just five points after Mainz beat Bayern.
And Tuchel is crediting the loss to Bayern at the beginning of the season for their renewed vigour.
“The reverse fixture showed that you can lose by a high margin because of small errors. But you can learn from that,” said BVB boss Tuchel.
“The 5-1 loss in Munich has made us into what we are now. And we are very happy with that.
“You could see our improvements in the games against Mainz and Augsburg following that loss in Munich.”
Dortmund, who are in the mix for Bundesliga, DFB-Pokal and Europa League success this term, pounced on Bayern’s defeat to Mainz by downing Darmstadt 2-0 on the same night.