Werder Bremen's 5-2 win against Bayer Leverkusen allowed the northerners to pull level but Bayern's superior goal difference allowed them to defend a once-commanding lead that has been gradually whittled down in the run-up to Christmas.

Exactly halfway through the season, Bayern have held onto the lead but coach Ottmar Hitzfeld will be perturbed at that his club has won only twice in seven Bundesliga fixtures while there have been hints of dressing room unrest.

Oliver Kahn was dropped as a result of his criticisms of his team-mates and his failure to stay at the club Christmas party until midnight but his deputy Michael Rensing kept a clean sheet, which proved enough to retain top spot.

Bremen came from behind to hammer in-form Leverkusen who led through Tranquillo Barnetta's early goal.

Ivan Klasnic scored twice and Diego, Clemens Fritz and Markus Rosenberg once apiece for Bremen before Stefan Kiessling struck a consolation.

Four points behind Bayern and Werder are Hamburg who drew 1-1 with Karlsruhe who led through Christian Timm before Ivica Olic's last-gasp leveller.

Champions Stuttgart signed off a memorable year with a 2-0 loss at Arminia Bielefeld.

Armin Veh's team snatched the German title from nowhere last season by winning their last eight games as Schalke and Werder Bremen faltered.

But the new season has seen them humbled in the Champions League and mounting a tame defence of their crown.

Jonas Kamper and Artur Wichniarek scored the goals for Arminia while Stuttgart were hampered by the sendings-off of Pavel Pardo and Ricardo Osorio.

A strike from Gerald Asamoah and an own goal from Marco Engelhardt earned Schalke a 2-1 win over Nurnberg for whom Angelos Charisteas found the net.

Wolfsburg walloped Borussia Dortmund 4-0 with Marcel Schafer, Ricardo Costa, Christian Gentner and Edin Dzeko the marksmen.

On Friday, Energie Cottbus' upturn in form continued with a 5-1 drubbing of Hannover.

The east German club was bottom of the Bundesliga heading into the match but benefited from strikes from Christian Bassila, Dennis Sorensen and Dimitar Rangelov inside the opening 45 minutes.

Daniel Ziebig added a fourth for Cottbus after the break before Thomas Kleine pulled one back for the beleaguered visitors on 68 minutes.

But a four-goal cushion was re-established within 60 seconds thanks to Rangelov's second of the night to ensure Cottbus' biggest top-flight win in five years.

On Sunday, Hansa Rostock host Bochum and Eintracht Frankfurt visit Duisburg.