Germany's worrying form ahead of Euro 2016 continued as they fell to a shock 3-1 defeat at the hands of Slovakia in Augsburg on Sunday.
Mario Gomez's penalty put the home team in front after 13 minutes, but a stunning strike from Marek Hamsik and a Michal Duris header turned the game on its head before the break.
After stormy weather had delayed the start of the second half, substitute Marc-Andre ter Stegen's dreadful mistake in wet conditions allowed Juraj Kucka to make it three and Germany could not find a way back into the match.
Joachim Low gave first caps to Bernd Leno and Joshua Kimmich, as well as substitutes Julian Weigl and Julian Brandt, but the head coach has major problems to solve with no more matches to play before he cuts his squad down from 27 to a final 23.
Germany, winners of the World Cup two years ago, have now lost four of their last six games and failed to keep a clean sheet for eight successive matches with the Euros under two weeks away.
They only have one more warm-up match against Hungary to play before the competition, while in-form Slovakia are unbeaten in seven as they prepare to face Northern Ireland in their last pre-tournament clash.
Jerome Boateng almost marked his first Germany appearance of 2016 with an early goal when his bouncing effort was tipped over the bar by Matus Kozacik.
But the hosts did not have to wait long to break the deadlock, with Mario Gotze drawing a foul from Kucka in the box and Gomez sending Kozacik the wrong way to make it two strikes in as many caps having previously gone almost four years without an international goal.
The world champions should have added to their lead, Leroy Sane seeing his effort from a promising opening saved by Kozacik's legs and Julian Draxler volleying over.
Slovakia levelled against the run of play in emphatic fashion four minutes before half-time when Hamsik gathered Ondrej Duda's pass and unleashed a blistering finish into the top corner from well outside the box, giving the debutant Leno no chance.
Astonishingly, the visitors then went ahead 185 seconds after levelling as Duris rose to powerfully head Vladimir Weiss' corner over Leno, who could not react quickly enough.
Low had made three changes at the interval and one of his replacements, Ter Stegen, had a moment to forget after 52 minutes when he somehow allowed Kucka's volley from Patrik Hrosovsky's corner to squirm through his legs.
Draxler was just off-target with a long-range drive for Germany, while Ter Stegen had to get out quickly to deny Hamsik.
After causing him problems for Slovakia's third goal, the wet surface helped the Barcelona goalkeeper on this occasion as it slowed the Napoli star down while he prepared to shoot.
The expected rally from Germany did not arrive in the closing stages, with Gotze firing wide in their best opening as Low's side failed to muster an attempt on target in the second half.