BERLIN -- Bayern Munich overcame a difficult start to beat Nuremberg 2-0 in the Bavarian derby and restore its 13-point advantage in the Bundesliga on Saturday, while Borussia Dortmund routed Werder Bremen 5-1.
Nuremberg struck the crossbar through Hiroshi Kiyotake in the fourth minute and forced several saves from Manuel Neuer before Mario Mandzukic scored with the visitors' first real chance in the 18th.
Mario Goetze sent David Alaba through on the left, and the Bayern defender crossed for Mandzukic to get ahead of his marker and convert.
The Croatian striker then crossed for Philipp Lahm to effectively seal the result in the 49th, ensuring Bayern stretched its league record unbeaten run to 45 games.
"It's a quality that Bayern scores one goal from one chance," Nuremberg coach Gertjan Verbeek said. "The momentum was then gone. The first half cost us a lot of energy and the belief wasn't quite as strong. After the quick second goal it was practically impossible."
Nuremberg was dealt two early blows when striker Daniel Ginczek and defender Timmy Chandler went off with injuries. The club said Ginczek was ruled out for the rest of the season after tearing the cruciate ligament in his right knee, while Chandler tore a meniscus in his left knee, keeping the United States defender out for eight to 10 weeks.
The home side was lucky not to go further behind in the 32nd. Arjen Robben struck the post from a free kick, Thomas Mueller struck the crossbar from the rebound and Mandzukic's follow up was blocked. Robben also struck the post in the second half.
"I quickly saw why Bayern has only won once in Nuremberg in the last six years," Bayern coach Pep Guardiola said. "Nuremberg played with a lot of aggression and intensity. They attacked very quickly and had two or three clear chances. It was easier for us after the second goal."
Two goals each from Henrikh Mkhitaryan and Robert Lewandowski, and another from Manuel Friedrich, ensured Dortmund stayed 17 points behind Bayern in third. Levent Aycicek scored Bremen's 89th-minute consolation on his Bundesliga debut.
Bremen coach Robin Dutt is coming under increasing pressure after the club's worst start to a Bundesliga season since 1974-75. Dutt took over last summer from Thomas Schaaf, who had been in charge for 14 years.
Lewandowski fired inside the far corner in the 26th and Mkhitaryan made it 2-0 in the 41st, when he skipped past several defenders before shooting beyond Raphael Wolf.
The unmarked Friedrich scored three minutes into the second half, Mkhitaryan crowned the win in the 62nd by curling the ball inside the far post after a delightful back-heel from Marco Reus, and Lewandowski claimed his second in the 85th, when he rounded the goalkeeper and fired through a defender's legs.
Midfielder Nuri Sahin referred to the confidence-boost the victory would give the side.
"The game was a lot of fun and when we have fun, then such results come out of it," Sahin said. "This big win is very important for us."
Bayer Leverkusen consolidated second place with a 1-0 win at Borussia Moenchengladbach on Friday.
Also, Wolfsburg beat Mainz 3-0, bottom side Eintracht Braunschweig lost 3-0 at Eintracht Frankfurt and Freiburg drew 1-1 with Hoffenheim.
Braunschweig appears to be doomed after slumping to its 14th defeat of the season, Wolfsburg bounced back from two straight defeats and boosted its chances of European football next season, and Freiburg was left to rue missed chances against Hoffenheim, for which Anthony Modeste equalized five minutes from time.
Hamburger SV, the only Bundesliga club to have played every season, edged closer to its first relegation with its sixth consecutive loss, a 3-0 defeat at home to Hertha Berlin in the late game.
"It's going to be brutally difficult until the 34th (last) matchday," said Hamburg goalkeeper Rene Adler, who saved Hertha striker Adrian Ramos' penalty in the 15th, only for Sami Allagui to score from the resulting corner.
Ramos scored with a header eight minutes later, and the Colombian striker claimed his league-leading 14th goal in the 39th.
Hamburg players were jeered by angry fans after fulltime.
"We have to live with it," said Hamburg captain Heiko Westermann, whose side remains second from bottom, four points above Braunschweig.