Schalke 04 suffered a shock 3-2 defeat at Hoffenheim on Saturday in the Bundesliga ahead of their Champions League clash at home to Arsenal on Tuesday after conceding a 91st-minute goal.
Hoffenheim picked up their first win in five games as super-sub Sven Schipplock netted the winner just two minutes after coming off the bench to leave the Royal Blues reeling before the Gunners' clash in Gelsenkirchen.
Having won 2-0 in London two weeks ago, Schalke warmed up for the return leg with their first defeat in nine games to rock the Royal Blues' confidence.
It had looked as though Schalke had rescued a point after Japan defender Atsuto Uchida had scored a late equaliser for the guests to make it 2-2 draw on 82 minutes.
Uchida enjoyed a simple tap in after a cross from Peru forward Jefferson Farfan found Holland's Klaas-Jan Huntelaar who gave his Japanese team-mate the simplest of chances with Hoffenheim goalkeeper Tim Wiese out of position.
But Schipplock hit the winner when played through to draw Schalke goalkeeper Lars Unnerstall and fire home in the 91st-minute.
Striker Kevin Volland put Hoffenheim ahead on 13 minutes before Schalke midfielder Roman Neustaedter levelled with a header after a final pass from Farfan.
Brazilian midfielder Roberto Firmino then converted a 67th-minute penalty after Volland was fouled in the box and it was the 21-year-old who provided the final pass for Schipplock to score the winner.
The victory moved Hoffenheim up to 13th while Schalke stay second, with Bayern Munich, who are at Hamburg on Saturday night, four-points clear at the top.
Eintracht Frankfurt remain third after their 1-1 draw with Guerth Fuerth on Friday.
Defending champions Borussia Dortmund are fourth after they were held to a goalless draw by VfB Stuttgart and remain four points behind Frankfurt.
Nuremberg won the battle of the basement teams as midfielder Timo Gebhart scored the winner with a 76th-minute header to move up to 14th and take some of the pressure off coach Dieter Hecking with their first win in seven games.
Hanover are sixth after their 2-0 win at home to Augsburg while Borussia Moenchengladbach were held to a 1-1 draw at their own ground by Freiburg.
On Sunday, fifth-placed Leverkusen host Fortuna Duesseldorf and Werder Bremen are home to Mainz 05.