Bundesliga champions VfL Wolfsburg slumped to a shock 4-2 defeat by Hamburg SV on Sunday, ending a 20-match unbeaten home record in the league stretching back to the 2007/8 season.
The win lifted Hamburg to second in the table with seven points from three games, behind leaders Bayer Leverkusen on goal difference.
Wolfsburg, who have six points, dropped to fourth while Bayern Munich are languishing in 14th following their 2-1 defeat by promoted Mainz on Saturday.
Hamburg stunned the hosts with two quick goals.
They went ahead in the fourth minute when Peruvian forward Paolo Guerrero's low drive bounced into the net off the back of Wolfsburg's Swiss keeper Diego Benaglio. Three minutes later, Dutchman Eljero Elia doubled the lead from close range.
Wolfsburg came out fighting in the second half, pulling a goal back seven minutes after the restart through midfielder Zvjezdan Misimovic's close range effort.
Nigerian new signing Obafemi Martins levelled for the hosts in the 56th with his second goal of the season.
Hamburg striker Mladen Petric put the visitors back in front with 15 minutes to go when he slid to connect with a Dennis Aogo cross in the box before Romeo Castelen added a fourth in the final minute.
Earlier VfL Bochum notched their first win of the season, beating Hertha Berlin 1-0 with a goal from Anthar Yahia.
The Algerian scored two minutes after the restart with a shot from the edge of the box after a freekick from Joel Epalle.
Hertha missed several chances to equalise in the second half but, as in every match this season, were lacking precision.
Werder Bremen beat Borussia Moenchengladbach 3-0 helped by two goals from Peruvian Claudio Pizarro who signed this week from Chelsea.