Robert Lewandowski's strike sent Bayern Munich back to the top of the Bundesliga but the European champions had to settle for a 1-1 draw at Union Berlin.
Grischa Promel's early header put Union in front at Stadion An der Alten Forsterei on Saturday, but they were unable to consign Bayern to what would have been a first defeat in 17 matches.
Lewandowski's 16th goal in as many games this season brought Hansi Flick's side level and neither team could force a winner in a pulsating contest.