Holders Borussia Dortmund suffered a shock exit from the German Cup at the hands of second-tier leaders St Pauli, losing 2-1 in the third round on Tuesday.
Etienne Amenyido gave St Pauli a fourth-minute lead from close range and Axel Witsel's own goal in the 40th minute doubled the hosts' advantage.
Erling Haaland's penalty just before the hour mark reduced the arrears but St Pauli hung on to reach the last eight and secure a first win over Dortmund for 33 years.
"We caused ourselves several problems in the opening 15 minutes and also conceded a goal straightaway. That's when it gets difficult," head coach Marco Rose said.
"The way we went about trying to score the equaliser in the first half was a little rash. After going 2-0 down, we adjusted a few things. But the key issue is how we, as the holders, started this cup battle. We didn't get that right."
In the night's other tie second-tier Karlsruher beat 1860 Munich 1-0 thanks to a Marvin Wanitzek penalty.