Thomas Tuchel’s side showed signs of nerves in the early stages and looked shaky in defence as Anthony Losilla headed over the crossbar. In contrast to Die Roten, Bochum were resolute at the back with last-ditch interventions being made to deny headers from Harry Kane and Matthijs de Ligt.
But Bayern were in no mood to allow Bochum parity for much longer, and broke through on the quarter-hour mark when Jamal Musiala worked enough space away from Ivan Ordets to smash the ball past Manuel Riemann.
Soon came a now time-honoured delay due to fan protests, and Noussair Mazraoui was replaced by Dayot Upamecano ahead of the restart.
However, Bochum seemed to benefit more from the interruption, with Musiala dispossessed and Losilla releasing Takuma Asano. The Japanese forward raced ahead and sent a pinpoint strike into the bottom corner to level the game.
Amazingly, it took just six more minutes for Die Unabsteigbaren to take the lead, as Keven Schlotterbeck rose uncontested to head home from Kevin Stoger’s corner delivery.
Despite 14 minutes of added time, Leon Goretzka heading into the side netting was the closest Bayern came to an equaliser before the break. That only increased expectations of a backs-to-the-wall job for Bochum after half time, and they continued to battle well before and after another interruption, with wideman Christopher Antwi-Adjei unrelenting in his defensive work.
Leroy Sane was introduced shortly after the hour mark as Bayern searched for a route back into the game, but he saw his venomous strike blocked.
Instead of Bayern building on that, however, things got even worse for the visitors when Upamecano found himself sent off in consecutive games. He earned a second yellow card for catching Schlotterbeck in the face inside the area and duly conceded a penalty, which Stoger converted despite Neuer getting a hand on it.
Kane slid the ball home following good work from Mathys Tel late on, but then saw a tame header saved as Bayern suffered a third consecutive defeat across all competitions for the first time since May 2015, leaving them eight points behind Bayer Leverkusen.
Though they were the pre-season favourites of many pundits to go down this year, the now 11th-placed Bochum are unbeaten in eight matches at the Ruhrstadion, in a run stretching back to November.
Flashscore Man of the Match: Kevin Stoger (Bochum)
