Bayern Munich returned to the top of the Bundesliga with a 4-1 win over FC Koln on the back of three goals in the opening 12 minutes.

RB Leipzig leapfrogged Bayern with a 3-0 victory over Werder Bremen, but Hansi Flick's side responded the following day by blowing away its opponent early on.

Thomas Muller laid on goals for Robert Lewandowski and Kingsley Coman before Serge Gnabry rifled in a third from a Joshua Kimmich corner.

Gnabry added a second 24 minutes from time, with Mark Uth pulling one back for Cologne.

Lewandowski reached 40 goals for club and country this season in the third minute, collecting a Muller pass and smashing into the roof of the net to make it 12 goals in 14 games against Cologne.

The home side was being cut open at will and Lewandowski and Muller were involved again when the latter found Coman, whose effort deflected in off Rafael Czichos to make it 2-0.

Bayern refused to let up and it had a three-goal lead when Gnabry brought down Kimmich's delivery to the far post and steered into the bottom-right corner of the net.

Only the woodwork prevented the Bavarian giant's lead from being greater at the interval as an off-balance Gnabry hit the crossbar and Timo Horn tipped Kimmich's long-range effort against the post.

Cologne might have found a way back had Jhon Cordoba not had two goals disallowed for offside inside the opening 10 minutes of the second half.

Bayern had eased off but scored a fourth in the 66th minute when Gnabry cut in off the left and curled home his second before Cologne finally got a consolation, Uth remaining onside to apply the finish to Florian Kainz's cross.

Gnabry squandered a glorious chance for his hat-trick when he fired wide after a lovely backheel from Muller, who missed out on a treble of assists in the process.