Hamburg have just six games left to avoid a historic first relegation from the Bundesliga as they dropped to second from bottom after Sunday's 3-1 defeat at Borussia Moenchengladbach.
As the only Bundesliga side to have never been relegated, Hamburg took a step closer to the second division at Gladbach after losing ten of their last 15 league matches.
Cameroon right-wing Jacques Zoua gave Hamburg a first-half lead before Borussia equalised when captain Filip Daems tapped home a penalty after goalkeeper Rene Adler saved his initial poorly-hit effort.
Gladbach made sure of the three points with two goals in the final five minutes when Brazil forward Raffael fired home a deft chip through from striker Max Kruse, then Spanish centre-back Alvaro Dominguez scored from a corner.
The defeat saw Hamburg replace VfB Stuttgart, who lost 3-2 at home to Borussia Dortmund on Saturday, in 17th of the league's 18 teams on goal difference while Gladbach are sixth.
Hamburg are on their third coach this season after Mirko Slomka took charge last month following Bert van Marwijk's dismissal in February while Thorsten Fink was sacked in September.
Elsewhere, Werder Bremen's Austria defender Sebastian Proedl headed home a 90th-minute winner to seal their 2-1 victory at Hanover 96 to keep his side 12th and eight points from the relegation places while hosts Hanover drop to 13th.
On Saturday, champions Bayern Munich dropped points for only the third time in the Bundesliga this season as they were held 3-3 at home by Hoffenheim.
Hoffenheim ended Bayern's record run of 19 consecutive Bundesliga wins, giving the Munich giants a wake-up call ahead of their Champions League quarter-final first leg at Manchester United on Tuesday.
Spain midfielder Thiago Alcantara has been ruled out of both quarter-final legs against United with a knee injury and is expected to miss the next six to eight weeks.
Bayern leaked three goals in a Bundesliga match for the first time this season after throwing away a 3-1 first-half lead following goals by veteran striker Claudio Pizarro and Swiss winger Xherdan Shaqiri.
Bosnia midfielder Sejad Salihovic curled in a 44th-minute free kick to make it 3-2 at the break after striker Anthony Modeste gave the guests an early lead.
Hoffenheim equalised on 75 minutes when Brazilian left winger Roberto Firmino darted on to a through ball and his shot beat both Bayern centre-back Dante and goalkeeper Tom Starke.
Despite the draw, Bayern still remain 23 points clear at the top of the table and extended their record unbeaten Bundesliga run to 53 matches.
- Dortmund fight back at Stuttgart -
Germany winger Marco Reus netted a hat-trick as second-placed Borussia Dortmund fought back from two goals down to win 3-2 at ten-man Stuttgart.
Dortmund, who face Real Madrid away on Wednesday in the Champions League quarter-finals, found themselves 2-0 down after just 20 minutes.
Christian Gentner and Martin Harnik took advantage of poor defending to net for the hosts before Reus scored all of the guests' goals.
Bayer Leverkusen hold on to fourth place despite drawing 1-1 at home to bottom side Eintracht Braunschweig as Sami Hyypia's side struggle for form with one win in their last 11 games.
Braunschweig took a shock lead through defender Ken Reichel just after the break before Stefan Kiessling slotted home a 53rd-minute penalty to spare Bayer's blushes.
Fifth-placed VfL Wolfsburg are just a point behind Leverkusen after their 2-1 win at home to Eintracht Frankfurt with Brazil defender Naldo scoring their 89th-minute winner.
Freiburg are unbeaten in their last four games as they enjoyed a 3-2 win at home to Nuremberg to move five points clear of the relegation zone.
Mainz remain seventh but in the hunt for a European place with a 3-0 win at home to Augsburg while on Friday Schalke 04 were 2-0 winners against Hertha Berlin.
Nigerian Chinedu Obasi put Schalke in front after 16 minutes with Dutch star Klaas-Jan Huntelaar adding the second goal just after the interval.
It was Huntelaar's 11th goal in 13 matches in a campaign disrupted by knee surgery.