The visitors grabbed the last-gasp winner through Rouwen Hennings to move onto 59 points, 10 ahead of third-placed Holstein Kiel who have three games left to play.
Duesseldorf coach Friedhelm Funkel extended his record for most promotions to the Bundesliga to six.
Nuremberg are in second place on 54 points and host Eintracht Braunschweig on Monday.
The top two win automatic promotion, while the third-placed team go into a two-leg relegation/promotion playoff against the Bundesliga's third-bottom team.
(Reporting by Karolos Grohmann; Editing by Ken Ferris)
