Now little Saarbrücken has knocked out two Bundesliga teams and made it to the quarter-finals.
"Just like against Bayern Munich, it's unreal," said Kai Brünker, who was wearing a face mask and made it 1-0 after just over an hour and showed two fingers to the fans.
Mispass by Hugo Larsson
Despite the mask, he nodded in 1-0 in the 20th minute but the referee disallowed the goal via VAR check because a Saarbrücken player pushed a Frankfurt player away.
Frankfurt's Swedish new signing Hugo Larsson played a weak pass that was intercepted by Saarbrücken and was able to make it 2-0 after that.
Now the upset team Saarbrücken is ready for the quarterfinals