Hamburg headed into this game knowing they needed a win to distance themselves from the bottom three, while Hertha similarly needed the win to further their survival hopes.
However, it was the visitors who started the better, and it took good work from Djourou to cut out an early move from Hertha.
At the other end, kraft was called into action in the 6th minute when a shot from Zoltan Stieber deflected and required a diving save.
Hamburg looked dangerous with the arial delivery throughout the entire first half. In the 12th minute, Cleber went close with a header after a corner from the left, and just seven minutes later Olic glanced wide.
That was after the ball had fallen to Rafael van der Vaart four minutes previously, but the Dutchman fired over in space inside the box.
The game was 0-0 at half time having descended into a real lull in the latter minutes. Both teams showed signs of intent, but in all truth the cutting edge and quality wasn't displayed by either side.
Two very frightened looking sides emerged from the tunnel for the second half, and another dull quarter of an hour ensued. The fear factor was clearly present, and even when Pierre-Michel Lasooga came on and HSV switched to two up front they couldn't fashion many chances.
Solomon Kalou had a chance for Hertha in the 64th minute as he headed straight at Adler from a Beerens cross, while minutes later Olic pounced on a loose ball inside the box before his square to Lasogga was cut out.
Haraguchi went close with a low shot straight at Adler in the 74th minute, and Olic had a shot deflected luckily wide, but there were few opportunities in a stale game.
As the game moved along, you got the sense it would take a game changing moment to force a goal.
It came in the 81st minute, when Cleber received his second yellow card for a push and was given his premature marching orders. On replay it seemed harsh, but perhaps it was for an accumulation of fouls.
Either way, Hertha were quick to capitalise and score the only goal of the game with just over five minutes left. A free-kick of the left side was delivered tantilisingly by Plattenhardt and met with a glance from Langkamp, directing it past Adler and sending the travelling fans into jubilation.
Stieber had a promising free-kick in the 90th minute, but he hit it well over the bar, and that would prove to be the last chance of the game.
Full time and the score was 1-0 in Hertha's favour. A sickening defeat for Zinnbauer's men, who remain rooted deep into trouble, while Pal Dardai's team have breathing space between themselves and the bottom three.
Questions will be asked of the HSV squad, and yet again their eternal Bundesliga status is in serious jeopardy, with Bayer Leverkusen away and Wolfsburg at home to follow.