When did Bayern Munich win their first competitive game under Barcelona's former manager?
2009–10 FC Bayern Munich season The 2009–10 season of Bayern Munich began on 1 July with their first training session, led by the team's new head coach Louis van Gaal. After several friendlies the first competitive game was a cup game on 1 August. The league started on 8 August.
2012–13 Bundesliga The 2012–13 Bundesliga was the 50th season of the Bundesliga, Germany's premier football league. The season began on 24 August 2012 with the season opening match at Westfalenstadion involving defending champions Borussia Dortmund and SV Werder Bremen and ended with the last games on 18 May 2013, with a winter break between the weekends around 15 December 2012 and 19 January 2013. Bayern Munich managed to secure the championship of the 2012–13 season after only 28 match days, beating their previous record by two matches.