Feb 7 (Reuters) - Runaway leaders Bayern Munich survived a torrid opening on their way to a 2-0 win over luckless Nuremberg who hit the bar and had two players carried off injured in the first half hour on Saturday.
Mario Mandzukic and captain Philipp Lahm, with his first Bayern goal in over three years, scored to give the Bavarians their 12th successive Bundesliga win.
Henrik Mkhitaryan and Robert Lewandowksi scored twice each as third-placed Borussia Dortmund thrashed hapless Werder Bremen 5-1 away, pushing the four-times champions closer to the relegation zone.
Defending champions Bayern lead with 56 points from 20 games with Bayer Leverkusen on 43 after their 1-0 win at Borussia Moenchengladbach on Friday. Dortmund are a further four points back in third. (Reporting By Brian Homewood)