Werder Bremen's title hopes suffered another setback when they crashed to a 2-1 at Mainz, a second consecutive league defeat.
Bremen's 40-year-old striker Claudio Pizarro scored their only goal.
After last Sunday's 6-2 drubbing at home by Leverkusen, Bremen were again outplayed as Mainz picked up their first win since mid-September to climb four places to 12th while Bremen drop to sixth - seven points adrift of leaders Dortmund.
Mainz took a deserved lead with 25 minutes gone when Daniel Brosinski whipped in a cross and Jean-Philippe Mateta fired under Bremen's goalkeeper Jiri Pavlenka.
The lead was doubled on 51 minutes when Ivory Coast forward Jean-Philippe Gbamin collected a Brosinski throw-in, darted back inside and drove his shot into the bottom corner.
However, Bremen brought on two strikers in Martin Harnik and Pizarro, who scored with 12 minutes left to claim his 194th goal on his 454th Bundesliga appearance.
With time running out Bremen captain Max Kruse forced the hosts' goalkeeper Robin Zentner into a stunning save as Mainz held on.