Sebastian Kehl fired the defending champions ahead within the forty eighth minute after Moritz Leitner split the Nürnberg defence and Lukasz Piszczek pulled the ball back for the Dortmund captain to drive in.
Lucas Barrios sealed the win within the 82nd minute, following up on a rebound to get his first goal of an injury-plagued season as Dortmund stretched their unbeaten run to 14 games.
Bayern Munich will reclaim the lead on goal distinction with a win at Hamburg on Saturday, when Schalke can also move level on 43 points at the highest with a win at home to Mainz.
