Champions Borussia Dortmund opened a three-point lead at the top of the Bundesliga after a 2-0 win at Nuremberg on Friday stretched their unbeaten run to 14 consecutive league games.
On a freezing Bavarian evening, with temperatures hovering around -15 Celsius, captain Sebastian Kehl gave his team a deserved lead in the 48th minute when he slotted the ball in with his left foot following a Lukasz Piszczek layoff.
Paraguay international Lucas Barrios, who turned down several offers of a move earlier this week, snatched his first goal of the season 10 minutes after coming on as a substitute, tapping in from two metres in the 82nd.
Dortmund, on a four-match winning streak, have 43 points from 20 matches. They are three points ahead of Bayern Munich, who travel to Hamburg on Saturday, and Schalke, who host Mainz the same day.