In the break, Anthony Modeste emerged as the hero, somehow missing an earlier chance to equalize. A goal from 17-year-old Youssoufa Moukok gave Dortmund hope after Bayern surged forward through Leon Goretzka and Leroy Sane either side of half-time.
The first half at the first sold-out Signal Iduna Park for Der Klassiker was not full of chances since before the pandemic and more than half an hour passed before either side registered a shot on target. That’s what happened for Dortmund when Manuel Neuer reacted well to push Raphael Guerreiro’s drive into the top corner of the far post.
Perhaps it stirred something at Bayern, as Goretzky’s opening goal came only a few minutes later. The goal was the result of good work down the left by Jamal Musiala, who drew defenders towards him before finding Goretzka on the edge of the box. His low shot back across his body grazed the grass and found the bottom corner.
Dortmund could have equalized straight away through Donyell Malen, but Neuer squared up again, closed the angle and smothered the shot with his body.
The home side also started the second half brightly and substitute Marius Wolf forced Neuer into a fingertip save from a rasping drive. From the resulting corner, the same player had a famous chance to equalize when Neuer misjudged the flight of the ball, but Wolf also missed it.
Bayern should have doubled their lead when Goretzky’s clever run and header produced a gaping goal for Sadio Mane. But his header narrowly missed the post.
Bayern’s eventual second was disappointing from Dortmund’s point of view when Leroy Sane’s long-range shot went through the hands of goalkeeper Alexander Meyer before hitting the net. But just after the hour mark, only Meyer’s chest block from point-blank range made it 3-0.
The reigning champions were made to rue the mistake as Moukoko struck well to halve the deficit. Dortmund quickly moved the ball forward from the back, Nico Schlotterbeck moved it forward and substitute Modeste linked up with Moukoko who fired hard past Neuer.
Modeste came so close to making it 2-2 after some great play on the wing from Karim Adeyemi. But just yards from goal, the experienced striker failed to get the right contact on the ball and then failed to react quickly enough as he swung towards Neuer.
Bayern were reduced to 10 men at the break when Kingsley Coman was sent off after receiving a second yellow card, giving Dortmund the last laugh.
Goalkeeper Meyer spent most of the final moments as a backup striker. But the chance to salvage a point seemed gone until Schlotterbeck stretched to keep the ball in play and chopped a cross to the back post for Modest to nod in the game’s final touch.