Borussia Dortmund moved up to second place in the Bundesliga by coming from behind to win 2-1 at Mainz.
The champions' coach Jurgen Klopp was facing his former club, who went in front after only four minutes through Marco Caligiuri.
Marco Reus replied in the 11th minute, though, and Robert Lewandowski got the winner two minutes before the break.
Schalke meanwhile dropped to third as they were held at home by fourth-placed Eintracht Frankfurt.
The Royal Blues had to settle for a 1-1 draw, after Klaas Jan Huntelaar's 11th-minute opener was cancelled out two minutes later by Stefan Aigner.
Frankfurt had Karim Matmour sent off in the 87th minute.
Elsewhere on Saturday, new Wolfsburg general manager Klaus Allofs made a quick return to his former workplace as the Wolves drew 1-1 with Werder Bremen.
The visitors went in front after 35 minutes through Marko Arnautovic, but had Lukas Schmitz sent off in the 62nd minute and conceded an equaliser to Bas Dost two minutes later.
Greuther Furth drew 0-0 at home to fellow strugglers Nurnberg.
Both sides had a man sent off, the visitors losing Markus Feulner after 35 minutes and Greuther Sercan Sararer after 61.
On Friday night, Fortuna Dusseldorf picked up their first home win in the Bundesliga this season as goals from Robbie Kruse and Stefan Reisinger saw off Hamburg 2-0.
Hamburg had two goals disallowed and they also lost influential midfielder Rafael van der Vaart to injury, but they could have no complaints about losing with the home side showing more fight.
Kruse put the promoted side in front in first-half stoppage-time before Reisinger struck in the 63rd minute to seal the points.
