Wendell was sent off for a foul in the penalty area and the home side subsequently collapsed, falling to a disheartening defeat to the Bundesliga strugglers at BayArena
Werder Bremen ran out surprise 3-1 winners over 10-man Bayer Leverkusen in Tuesday's DFB-Pokal quarter-final.
The visitors came into the meeting at BayArena in the relegation play-off spot in the Bundesilga, while Leverkusen are currently chasing Champions League qualification.
And the match seemed to be going to form when Javier Hernandez opened the scoring from the penalty spot, but the hosts were soon pegged back by Santiago Garcia.
It went from bad to worse for Leverkusen just before half-time as Wendell was sent off for a foul on Fin Bartels in the penalty area and Claudio Pizarro tucked away the resulting spot-kick.
A man light in the second period - and shorn of Hernandez, who limped off injured - Leverkusen struggled to force a way back into the game and their third consecutive quarter-final exit was sealed eight minutes from time by Florian Grillitsch - despite the star appearing to have moved into an offside position.
- Goal