VfL Wolfsburg battled their way past Schalke 04 1-0 on Wednesday to reach the German Cup quarterfinals along with RB Leipzig, who crushed second division VfL Bochum 4-0 with a double from Yussuf Poulsen.
The in-form Wolves, in third place in the Bundesliga, have won their last four games in all competitions without conceding a goal.
Schalke keeper Ralf Faehrmann did well to save Wout Weghorst's 40th-minute penalty but the Dutchman stabbed in on the rebound for the winner.
The Royal Blues, in last place in the league, should have equalised on the stroke of halftime but American teenager Matthew Hoppe was denied from close range by keeper Koen Casteels with a sensational reflex save.
Schalke battled hard and had their share of chances after the break, going close again through Mark Uth midway through the second half, but the striker failed to connect with a cutback in front of goal.
Despite a frantic finale and pressure from Schalke, Wolfsburg managed to hold on for the win.