Hamburg moved out of the bottom three thanks to an away victory over last-placed Kaiserslautern, who are now 10 points adrift of safety with six games of the season remaining.
Marcell Jansen scored the only goal of the game in the 28th minute as the northern Germany side reversed their slide down the table, leaving the Red Devils with a mountain to climb to avoid relegation to the second division.
Their new coach Krassimir Balakov has now lost both of his games in charge with Kaiserslautern's last league win now 19 games ago.
The early exchanges were typical of a relegation battle with neither side prepared to take any risks, preferring instead to keep possession as far away as possible from their own goal.
Chances were few and far between with the first coming in the 11th minute when Kaiserslautern midfielder Pierre De Wit's shot was deflected by Michael Mancienne, making the save a difficult one for Jaroslav Drobny.
Drobny denied De Wit once again in the 24th minute before Hamburg took their first real chance of the game to go ahead.
Ivo Ilicevic's shot was blocked by Anthar Yahia's hand, but the referee let play continue as the ball fell for Jansen to score.
Hamburg nearly made it two early in the second half when Mladen Petric's shot was saved well by Tobias Sippel, but he failed to keep hold of the ball and Jansen nearly converted his second rebound of the game, but he missed the target this time.
Drobny then pushed Olcay Sahan's effort over the crossbar as Kaiserslautern came back at Hamburg.
Konstantinos Fortounis and Sandro Wagner both missed the targets with shots from distance as the home side tried to find a way back into the game while Hamburg retreated to preserve their lead.
They had the chance to seal the win on the counter-attack in the 82nd minute, but Heung-Min Son and Jansen got in each other's way and the chance was lost, although Hamburg still held on to win the game.