Union were hoping to end their miserable run which has seen relegation fears worsen, but were coming up against a Leverkusen side who had won six of their last seven matches in all competitions (D1), including a 2-0 success away to Olympiacos in the first leg of their UEFA Champions League play-off tie in midweek.
Despite their game in Greece taking place less than 72 hours previously, Kasper Hjulmand’s men showed no signs of fatigue as they settled quickly here in what was a stop-start affair in the early stages in the German capital.
Following two early bookings, Union were forced into an early change on 11 minutes after Janik Haberer - one of those cautioned - was forced off and replaced by Christopher Trimmel.
Despite dominating possession, Die Werkself struggled to break down the Union defence and found themselves behind at the break. Ajoscha Kemlein’s long ball caused havoc in the Leverkusen defence which allowed Rani Khedira to capitalise and fire home his second goal in four matches.
The second half was slow to get going as the visitors’ struggles continued. Their first opportunity came when Ibrahim Maza drifted towards the box and let fly, but Frederik Rønnow was on hand to make the save.
Hjulmand was clearly not happy with his side’s performance, as he made a triple change on the hour mark which introduced last week’s goalscorers Patrik Schick and Ernest Poku, but they did not have the desired effect as Union’s rearguard continued to stand firm.
The home side controlled the remaining half-hour with little trouble, as Leverkusen mustered just one effort on target over 90 minutes, perhaps with an eye on their European commitments in midweek.
The defeat damages their pursuit of a top-four finish, as they sit three points behind fourth-place Stuttgart. Union, meanwhile, move into the top half of the table with their first victory in over two months.
Flashscore Man of the Match: Rani Khedira (Union Berlin)