Hamburger SV have claimed a surprise 2-0 half-time lead over Borussia Dortmund.
Despite Dortmund controlling the game for much of the early stages, the hosts could have broken the deadlock against the run of play when a loose ball fell to Ivo Ilicevic, whose poor touch allowed the visiting defence to recover.
Hamburg started to improve in possession and they were gifted the chance to take the lead when Roman Burki was adjudged to have brought down Ilicevic, despite replays suggesting that there was no contact.
Pierre-Michel Lasogga stepped up from 12 yards and he fired home calmly to hand the advantage to Bruno Labbadia's side.
Dortmund attempted to hit back immediately in a fast break which ended with Marco Reus seeing Rene Adler push his powerful strike past the post.
However, Hamburg broke up play well to limit the space on offer and the lead was doubled when Lewis Holtby slotted home after being teed up by Nicolai Muller.
