Borussia Dortmund are 10 points clear in the Bundesliga after a 2-0 win over Nuremburg on Sunday, while Bayer Leverkusen also won.
Central defender Mats Hummels connected with a Nuri Sahin free kick to head visitors Dortmund in front in the 23rd minute at the Frankenstadion.
Nuremburg restricted the runaway leaders to just one goal for the bulk of the match but they were unable to equalise.
Poland international Robert Lewandowski had no such problems, striking two minutes from time to seal the win for Dortmund.
Jurgen Klopp's side are now 10 points clear at the top, following second-place Mainz' loss to Frankfurt on Saturday.
Bayer Leverkusen regained third place with a 3-2 win at home to Cologne.
Patrick Helmes opened the scoring for the home side 21 minutes in at the BayArena, but the lead lasted just six minutes before Pedro Geromel latched on to a Lukas Podolski free kick to equalise.
Switzerland international Tranquillo Barnetta restored Leverkusen's lead 10 minutes into the second half and Stefan Reinartz established a two-goal cushion with a close-range header shortly afterwards.
Podolski was involved again as Martin Lanig pulled one back for Cologne in the 65th minute, but Leverkusen, well led by Brazilian Renato Augusto, survived a nervous finish to secure all three points.
Cologne had managed a draw and a win in their previous two matches, but their ninth defeat of the season leaves them second from bottom, and four points from safety.