Visitors Turkey shocked Euro 2024 hosts Germany 3-2 in a friendly on Saturday to spoil coach Julian Nagelsmann's home debut after taking the job in September.
The Germans, racing to get a strong team together for next year's tournament on home soil, still have a way to go and their leaking defence remains a major cause for concern.
They made a strong start and took a fifth-minute lead when forward Kai Havertz tapped in a Leroy Sane cutback in front of a sold-out 70Â 000 crowd.
The visitors made the most of a string of defensive errors to hit back with goals from Ferdi Kadioglu in the 38th minute and 18-year-old former Bayern Munich youth player Kenan Yildiz in first-half stoppage time.
Niclas Fuellkrug levelled three minutes after the restart with a low shot following Florian Wirtz's solo run for his 10th goal in 12 internationals for Germany.
The Turks, who have qualified for Euro 2024, refused to settle for a draw, however, and Salih Ozcan hit the post before they earned a 70th-minute penalty for a hand ball by Havertz which Yusuf Sari converted.
Germany face Austria on Tuesday in another friendly