Borussia Dortmund missed the chance to record a fifth successive Bundesliga win as Hamburger SV earned a valuable goalless draw in their battle to avoid relegation.
It was Josef Zinnbauer's side who looked most dangerous in the early stages, despite spending long spells of the first half allowing Dortmund to dominate possession.
A moment of hesitation in the visiting defence allowed Valon Behrami to find the space to drag an effort past the post, before Mohamed Gouaida sent a shot over after meeting Nicolai Muller's inviting cross.
Dortmund improved before the break as the pace of Pierre-Emerick Aubameyang started to have an impact on the game, but the Gabon international was left frustrated when Jaroslav Drobny got a strong hand to his powerful strike.
Jurgen Klopp watched his side control the tempo throughout the second half, with substitute Kevin Kampl hitting a tame effort wide before Marco Reus just missed the target after finding space in a congested box.
Reus was proving to be a constant threat to a vulnerable Hamburg defence, and he almost provided an assist for Aubameyang, who could only send a header wide of the post.
A Zoltan Stieber free kick forced Roman Weidenfeller into a save at the other end, but the hosts struggled to build any pressure as Dortmund continued to press for the winner.
However, the Hamburg back four stuck to their task admirably, and Dortmund were forced to settle for a point as the home side moved a step further away from the bottom three in the Bundesliga table.
