US international Bobby Wood scored Hamburg's winner on Sunday as their revival continued with a 2-1 comeback victory over Borussia Moenchengladbach.
Hamburg, the Bundesliga's only ever-present side since its inception in 1963-64, have picked up 13 points in their last six games under Markus Gisdol.
However, they remain 16th -- in the relegation play-off place -- having taken just two points from their first 10 matches in a disastrous start to the season.
Gladbach took the lead in Hamburg when Denmark defender Andreas Christensen headed home with 22 minutes gone, but the hosts drew level when Serbia's Filip Kostic nodded in from a cross 14 minutes later.
American striker Wood hit the winner 10 minutes from time when he crashed his shot past Gladbach goalkeeper Yann Sommer.
Referee Deniz Aytekin, heavily criticised for his performance in Barcelona's stunning 6-1 win over Paris Saint-Germain in the Champions League on Wednesday, correctly disallowed two Hamburg goals from Wood and Lewis Holtby.
Earlier, Austria striker Guido Bergstaller netted twice as Schalke 04 snapped their six-match winless streak with a 3-0 victory at home to Augsburg.
Schalke coach Markus Weinzierl had an enjoyable afternoon against his former club as the Royal Blues wrapped up the win with just over half an hour played in Gelsenkirchen.
"We put in a very strong first half -- I must pay the team a big compliment," said Weinzierl, whose side next travel to Borussia Moenchengladbach for the second leg of their Europa League last-16 tie following Thursday's 1-1 draw.
"In the second half, you could see we had a few games in our legs.
"A lot of people have written us off in the Europa League, but we still believe in our chances," he added.
Burgstaller opened the scoring with four minutes gone when he stabbed home at the far post from a corner. He then grabbed his second on 29 minutes after a cross from Cameroon's Eric Choupo-Moting.
Schalke captain Benedikt Hoewedes conceded a penalty by fouling Augsburg striker Raul Bobadilla, but goalkeeper Ralf Faehrmann saved Paul Verhaegh's spot kick on 32 minutes.
Attacking midfielder Daniel Caligiuri then netted the Schalke's third goal just two minutes later.
The victory halted Schalke's slide down the table. They climbed two places to 11th, two points ahead of Augsburg.
It also relieved some of the pressure on Schalke coach Weinzierl, who came increasingly under fire following last weekend's 4-2 league defeat at Borussia Moenchengladbach.
At the top of the table, leaders Bayern Munich extended their lead to 10 points on Saturday after their 3-0 win over Eintracht Frankfurt on a red-letter day for the Bavarian giants as their nearest rivals lost.
Second-placed RB Leipzig crashed to a shock 1-0 defeat at home to Wolfsburg, while Borussia Dortmund, who are third, suffered a Champions League hangover in the capital as they lost 2-1 at Hertha Berlin.