On that weekend, they had lost to Bayer Leverkusen, who currently sit fifth - but solely on goal difference - as just four points separate Germany's top ten sides after seven match days.
Robert Lewandowski continued his excellent goal-scoring form; now having netted 15 goals in all competitions this term. However, just four days after thumping Tottenham 7-2 in North London, Niko Kovac's men were unable to secure another domestic victory before the international break.
Without further ado, let's look at three reasons why Bayern succumbed to their first league defeat of the 2019/20 season:
#3 Wastefulness in front of goal
After such a clinical display in midweek, it's understandable that Bayern wouldn't have been at their brilliant best in front of goal on this occasion. However, they registered 20 shots, which was more than double of Hoffenheim's eight over the 90 minutes.
The visitors had five on target, which was one more than the Bavarian giants, while utilizing their opportunities better to devastating effect. Serge Gnabry had his opener cruelly ruled out for offside in the build-up, before both he and Thiago Alcantara were denied by Oliver Baumann's timely double save a minute later.
Corentin Tolisso, Kingsley Coman and Philippe Coutinho all had efforts flying narrowly wide before the interval. So by the time Adamyan broke the deadlock - ten minutes after the restart - the hosts would have been right to question their profligacy in front of goal.
Lewandowski finally got on the score sheet after 73 minutes, converting Thomas Muller's delivery from close-range with a chance he simply couldn't miss, but it was more relief than jubilation when they leveled the scoring.
Gnabry came close late on, but Hoffenheim held firm to record a memorable win. This was only the second time Bayern have scored just one goal in a game this season.