RB Leipzig, last season's Bundesliga runners-up, slumped to a 2-1 defeat at in-form Union Berlin on Friday for their third consecutive league loss that kept them in eighth place and piled the pressure on coach Jesse Marsch.
Leipzig, already eliminated from the Champions League, have now lost three league matches in a row for the first time in their top division history and are already 13 points off the pacesetters.
Marsch, who joined this season to replace Julian Nagelsmann, has seen his team win five of their 14 league games this term.
The latest loss puts the American, who was not at the match due to being in COVID-19 quarantine, under more strain.
Union, who moved up to fourth, took the lead when Taiwo Awoniyi stabbed the ball in at the far post after six minutes.
Union missed several golden chances in a strong finish but Leipzig keeper Peter Gulacsi pulled off several stunning saves to keep the score down.