German champions Bayern Munich started their new season with a 2-0 win over Borussia Dortmund in the Bundesliga opening game played in the Allianz Arena on Friday. Roy Makaay notched Bayern's first goal in the 24th minute before a second half goal from Bastian Schweinsteiger sealed the opening win for the Bavarians in the game that saw keeper Oliver Kahn celebrates his 500th Bundesliga game. The champions who were experiencing life without Michael Ballack attacked from early on and Schweinsteiger had a great chance to score in the 13th minute after the ball felt to him in the box following good footwork from Makaay but Roman Weidenfeller intercepted the ball bravely. One minute later, Willy Sagnol almost scored an own goal when his miscued clearance hit the bar before Nelson Valdez played a clever heel to Alexander Frei whose backward kick went just inches over. Bayern scored their first in the 24th minute through Makaay after the Dutch striker fired a low swerved shot from the edge of the box in the back of the Dortmund net. Dortmund had a great chance to equalize when Owen Hargreaves' back pass felt to Valdez but his quickly taken shot was saved by Kahn. Bayern started the second half brightly and Schweinsteiger added their second from a powerful low shot after receiving Philipp Lahm's pass on the edge of the area. Dortmund made some efforts to pull a goal back and Dede almost found the net but the Brazilian's header was saved by Kahn. Dortmund's best chance of the game came to Valdez after Florian Kringe released him with a great ball but the Paraguayan hit his volley towards Kahn's legs. Bayern could have added a third after a lovely pass-exchange between Makaay and Roque Santa Cruz ended with a powerful shot from the Dutch but Weidenfeller saved Dortmund from a heavy defeat.