Bayern Munich became the first team to win their opening nine games of a Bundesliga season on Saturday as a first-half Thomas Mueller strike proved enough for Pep Guardiola's side to beat Werder Bremen 1-0.

Mueller stole in front of Alejandro Galvez to control a Thiago Alcantara cross at the near post and stab past Felix Wiedwald for the only goal of the game, his ninth of the season, at the Weserstadion as Bayern made more Bundesliga history.

That was despite in-form Robert Lewandowski, having netted 15 times in his previous six games for club and country, for once failing to score.

However, the Pole felt he should have had a penalty in the second half after being taken out by Wiedwald when through on goal, and Mueller's solitary strike sufficed to condemn Bremen to a club record-equalling fifth consecutive defeat.

The win, their 999th in the Bundesliga, set Bayern up nicely for their trip to face Arsenal in the Champions League in midweek and saw them once again move seven points clear at the top of the table from nearest challengers Borussia Dortmund, who won 2-0 at Mainz on Friday.

Dortmund coach Thomas Tuchel returned to face his former club and saw Marco Reus put the visitors in front in the first half.

The Germany star then had a second-half penalty saved but Henrikh Mkhitaryan made sure of the three points late on as Borussia bounced back from their 5-1 hiding at the hands of Bayern in their last outing to register a first win in five.

Germany striker Max Kruse scored his first career hat-trick as Wolfsburg climbed up to fourth with a dramatic 4-2 win at home to Hoffenheim at the Volkswagen Arena.

Dieter Hecking was taking charge of a Bundesliga game for the 300th time and saw his side open the scoring with just 41 seconds played when Julian Draxler squared for Kruse to score.

Draxler then crossed for Bas Dost to head in the second goal inside seven minutes but Hoffenheim fought back, Jeremy Toljan reducing the deficit before Jonathan Schmid converted at the second attempt to level matters on 54 minutes.

But Kruse, who came off the bench to score the winner for Germany against Georgia in Euro 2016 qualifying last weekend, put the Wolves back in front from a Luiz Gustavo assist just after the hour mark and then completed his hat-trick late on.

Schalke 04 are third, just a point behind their Ruhr rivals Dortmund, after Max Meyer struck a stoppage-time winner to see off Hertha Berlin 2-1.

Benedikt Hoewedes had earlier headed the Royal Blues in front but Salomon Kalou's 73rd-minute header looked set to earn Hertha a share of the spoils.

Meanwhile, Bayer Leverkusen were held to a 0-0 draw at Hamburg and promoted Darmstadt's good start to life in the top half continued with a 2-0 victory at Augsburg.

Sandro Wagner and Peter Niemeyer both netted in the first half as Darmstadt climbed into the top half of the table and left Augsburg, who are in this season's Europa League, third from bottom.

Eintracht Frankfurt host Borussia Moenchengladbach in Saturday's late game before Cologne entertain Hanover 96 and Ingolstadt go to bottom club VfB Stuttgart on Sunday.