Hamburg missed a chance to pull even on points with leaders Wolfsburg for at least one night in a loss at Borussia Dortmund, who remained alive in the running for European football next season.
Sebastian Kehl struck the first goal for Dortmund in the 32nd minute and Alexander Frei converted a penalty in the 90th minute to keep Dortmund undefeated at home this season.
Dortmund's fifth consecutive victory gives Jurgen Klopp's team 49 points in seventh place - five points behind a trio of teams with 54 points in third to fifth place.
Hamburg dropped to fifth with their second loss in the last three games on 54 points - three points behind leaders Wolfsburg, who play Cottbus on Sunday.
Dortmund had the ball in the net in the 14th minute as Tamas Hajnal blasted home a volleyed rebound but the goal was disallowed for offside.
The hosts were close to grabbing the lead eight minutes later but Neven Subotic's 30-yarder struck the upper half of the crossbar.
Dortmund finally pulled ahead in the 32nd on a fine goal by Kehl. Nuri Sahin played a high ball over the backline to the defender Kehl, who hit a low volley through the legs of Hamburg goalkeeper Frank Rost from eight yards out.
With 10 minutes left, Hamburg nearly equalised as Dortmund keeper Roman Weidenfeller was far from his goal and substitute Ivica Olic looped a pass over to him to Albert Streit, whose shot from three yards came back off the lower half of the bar and just off the left post.
Dortmund finished off the visitors in the last minute on a penalty.
Michael Gravgaard took down Kevin-Prince Boateng on the left edge of the area, and Frei stepped up to the spot and beat Rost to the left side for the winner.
