Sebastian Kehl and Lucas Barrio scored in 0, on Friday to return to top of the Bundesliga.

Defending champion Dortmund broke a three-way tie on points with Bayern Munich and Schalke as it grabbed sole possession of the top spot ahead of the weekend matches.

Bayern entered the week with the top spot based on goal differential, and will return to the summit with a win Saturday at Hamburg.

Dortmund survived a couple scares early as Shinji Kagawa cleared Timmy Simons' cross off the line in the 11th minute, and then Tomas Pekhart launched an open chance well high from the edge of the 6-yard box in the 19th.

Robert Lewandowski had Dortmund's first opportunity in the 21st, but Nurnberg goalie Raphael Schafer made the first of four saves.

Kevin Grosskreutz wasted a second chance for Dortmund in the 26th, and Schafer made another fine save on Lewandowski in the 34th, before stopping a weak shot from Kagawa in the 36th.

Dortmund's breakthrough came early in the second half in frigid Nurnberg, as a final pass from Lukasz Piszczek was deposited by Kehl to the bottom left.

Nurnberg rarely threatened, and Dortmund poked a second past Schafer with just 8 minutes remaining as Barrios latched onto a rebound to score his first goal.

Dortmund's fifth straight win put pressure on Bayern as it heads to Hamburg on Saturday with concerns defensively.

Daniel van Buyten was lost to injury last month and Rafinha is banned, so Jupp Heynckes will likely be forced to move Luiz Gustavo or Anatoliy Tymoshchuk for cover in the backline, either at center back or right back.

"It's very irritating," Bayern's Jerome Boateng said, "to be without both Van Buyten and Rafinha."

Hamburg has been revived under Thorsten Fink, a former Bayern player. Hamburg was unbeaten in his first eight matches in charge, and the club has climbed to mid-table in 11th after a horrible start.

Although matches are being threatened through Europe due to extreme cold, five more fixtures are also slated for Saturday: Bayer Leverkusen hosts Stuttgart, Hertha Berlin hosts Hannover, Hoffenheim hosts Augsburg, Schalke hosts Mainz, and Wolfsburg hosts Monchengladbach.

On Sunday, Freiburg hosts Werder Bremen and Kaiserslautern hosts Cologne.