VfL Wolfsburg won an astonishing match at VfB Stuttgart, striking in the 90th minute after the hosts had a penalty saved and missed an open goal two minutes earlier.
The two other promoted sides won as two goals from Dani Schahin helped Fortuna Dusseldorf win 2-0 at Augsburg on their return to the top flight after a 15-year absence while Eintracht Frankfurt beat Bayer Leverkusen 2-1
The most dramatic match was at Stuttgart, where the home team's Vedad Ibisevic had an 88th-minute penalty saved by Diego Benaglio then incredibly fired the rebound wide from three metres with the goal at his mercy.
Ibisevic was still shaking his head in disbelief when Bas Dost headed in Vierinha's cross to give Wolfsburg the points.
Bayern, haunted by last season's disappointments when they finished as runners-up in the Champions League, Bundesliga and German Cup, struggled against feisty Fuerth until Thomas Muller fired them in front two minutes before half-time.
Bayern, who began with Bastian Schweinsteiger on the bench after a summer of fitness problems, Franck Ribery sidelined with flu and Mario Gomez injured, went ahead when Dante's header was cleared off the line and Muller scored from close range from the rebound.
"I was very optimistic, they have great motivation, you could see it in training and in the preparation matches," said Bayern coach Jupp Heynckes. "It wasn't easy to start with, as we expected, but we controlled the match after the first goal."
