Sebastian Langkamp grabbed a last-gasp winner for Hertha Berlin as they piled the pressure on 10-man Hamburg at the Volksparstadion on Friday night.
The Hertha defender headed in the only goal of the game only minutes after the hosts had been reduced to 10 men with Cleber given his marching orders for a second yellow card.
The game between two of the Bundesliga's strugglers had seemed set to end in a stalemate until Langkamp's 86th-minute winner took the Old Lady above Hannover in the standings and left Hamburg still just two points above the bottom three.
The hosts had a good command of the game in the first half, but for all of their efforts they lacked a goal.
Zoltan Stieber went closest with his shot which deflected off John Anthony Brooks and needed a fine save from Thomas Kraft to keep out.
Ivica Olic and Rafael van der Vaart both provided further shots on goal in a one-sided first 45 minutes.
Hertha coach Pal Dardai was rather animated on the sideline as he demanded more from his team, but he did not get it until the hour mark, when Salomon Kalou was the first to test Rene Adler in the Hamburg goal with a close-range header.
Back at the other end, Olic sent a shot into the side-netting with Pierre-Michel Lasogga missing the chance to mark his return after injury as he saw a shot blocked.
With just under 10 minutes to go, Cleber was given his marching orders for a second yellow card.
That left a gap at the back for Hamburg and, with their next attack of the game, Hertha exploited it to perfection with Langkamp rising to meet Marvin Plattenhardt's sweeping free-kick and head in a crucial winner for the Old Lady.
The home team were booed off at the final whistle with their top-flight status still hanging in the balance.