GELSENKIRCHEN, March 2 (Bundesliga) - Hamburg's fourth consecutive win lifted them further away from the relegation zone and left a large dent in Schalke's hopes of winning the Bundesliga this season.
Goals from Rafael van der Vaart and Ivica Olic inside the last 20 minutes took the visitors up to 10th in the table and four points clear of the drop zone.
Schalke, on the other hand, could see their lead at the top of the table cut to a single point this weekend after losing their third game in the last four.
Stuttgart, Werder Bremen and Bayern Munich will all be looking to close the gap when they play on Saturday.
Schalke coach Mirko Slomka had demanded a win from his side to ``send out a warning'' to their title rivals.
And Hamburg goalkeeper Frank Rost, who joined the north Germany club from Schalke in January, was given his first warning from a Hamit Altintop free-kick which he did well to palm on to the post.
Dario Rodriguez also tested Rost in a bright start for the home side.
Hamburg were able to contain the pressure though, and slow down the tempo of the game to suit their style.
After an hour of tight battles in midfield, the game sprang into life inside the last 20 minutes with the home side the first to come close to breaking the deadlock.
Rost was called into action to thwart the home side's first really dangerous attack of the second half, and from his long punt forward, Van Der Vaart was gifted the chance to put Hamburg in front.
Fabian Ernst and Rodriguez both left the ball for each other, allowing the Dutch midfielder to collect Rost's kick in front of Manuel Neuer and fire into the bottom corner from 10 yards.
A similar defensive error allowed Olic to double the visitors' lead 10 minutes later.
Marcelo Bordon and Mladen Krstajic were both attracted to David Jarolim, leaving Olic free to the Hamburg midfielder's left.
Jarolim was first to the ball and immediately slid it into the path of Olic, who coolly beat Neuer from 10 yards.
Kobiaschwili's last-minute free-kick, which deflected just inches wide of the post, was the closest the hosts came to providing any joy to their fans.