Bayern went into the game on a 15-match winning streak - nine games on the run-in to the 2004-05 title and the first six this season - but only a series of saves from Oliver Kahn spared them a heavier defeat.
Hamburg enjoyed a slice of luck to take the lead while the sides were still settling. Trochowski played a ball towards the Bayern goal and a lunge from Ali Karimi deflected the ball into the path of Van der Vaart, who calmly beat Kahn.
Bayern had the Germany captain, Michael Ballack, back in midfield but, with Roy Makaay once again looking well short of his best, they rarely troubled the Hamburg goal keeper Stefan Waechter and wasted chances when they came. In the 62nd minute Sergei Barbarez slid a pass through to Trochowski, who stroked a shotinto the top corner of the net.
Third-placed Werder Bremen won 2-1 at home to Bayer Leverkusen, with goals from Miroslav Klose and Ivan Klasnic.Reuse content