Thomas Tuchel's charges were poor over 120 minutes and needed spot-kicks to seal their place in the next round
Goalkeeper Roman Weidenfeller spared Borussia Dortmund's blushes with a pair of shootout saves to help them progress to the third round of DFB-Pokal after a 1-1 draw with Union Berlin.
Weidenfeller expertly saved Union's first two penalties before Philipp Hosiner struck the crossbar to give Dortmund a 3-0 spot-kick triumph following a gruelling 120-minute encounter with their in-form second-tier opponents.
A first-half own goal by Michael Parensen looked set to be enough to see the hosts advance, before Steven Skrzybski scored a sensational equaliser for Union with 10 minutes of normal time to play and forced Weidenfeller to be the hero.