Bayern see off Royal Blues to maintain Bundesliga lead September 22, 2012 -- Updated 1629 GMT (0029 HKT) Bayern's players celebrate a goal for Thomas Mueller in their impressive win over Schalke in the Bundesliga. Bayern Munich win 2-0 at Schalke in Germany's Bundesliga Bavarian giants have 100 per cent record after four games Champions Borussia Dortmund beaten 3-2 at Hamburg to end unbeaten run Surprise packet Eintracht Frankfurt level on points at top with Bayern (CNN) -- Bayern Munich continued their 100 per cent start to the Bundesliga season with an impressive 2-0 win over Schalke in Gelsenkirchen Saturday. The heavyweight clash before a capacity crowd at the Veltins Arena was expected to be a testing encounter for Jupp Heynckes team, but two goals just short of the hour mark from Tony Kroos and Thomas Mueller eased their passage. It left Bayern on a maximum 12 points after four games, heading Eintracht Frankfurt, 2-1 winners at Nuremberg Friday, on goal difference. Two-time defending champions Borussia Dortmund lost ground with a 3-2 defeat at Hamburg to leave them five points adrift of the leading pair. Bayern had been the better side in the first half with the Royal Blues of Schalke unable to create a clear cut opening. German international pair Kroos and Mueller looked dangerous throughout and it was their combination that led to the 55th minute opener. Mueller played in Kroos to beat Lars Unnerstall with a low shot and three minutes later he was also on the score sheet with a fine individual goal. Mueller might have scored a second with a clever back heel, but his team were already guaranteed three points to follow on from their impressive 2-1 Champions Leauge win over Valencia in midweek. Meanwhile, Dortmund's 31-match unbeaten run came to an abrupt end at struggling Hamburg, who had been without a win. South Korea's Son Heung-Min scored twice for the home side, including the clinching third. Ivo Ilicevic was also on target for the northerners while Croatia's Ivan Perisic twice equalized for Dortmund. Mainz also secured their first win of the season as they beat Augsburg 2-0, while in other matches Fortuna Duesseldorf and Freiburg were goalless and Felix Magath's Wolfsburg drew 1-1 with promoted Greuther Fuerth.