Borussia Dortmund returned to within five points of league leaders Bayern Munich as Thomas Tuchel got one over his former club Mainz with a 2-0 win.
Marco Reus put Dortmund in front after half an hour and Shinji Kagawa made sure of the points midway through the second half.
The win ensures the Westphalians keep up the pressure on Bayern with eight games of the season remaining, while they are now just four points away from securing their return to the Champions League.
Bayer Leverkusen returned to winning ways on Roger Schmidt's return to the touchline with a 1-0 win over Hamburg.
The team had lost their way during Schmidt's suspension, losing two and drawing one, but they bounced back thanks to an Albin Ekdal own goal in the 18th minute.