- Kai Havertz (5')
- Niclas Füllkrug (49')
- Ferdi Kadioglu (38')
- Kenan Yildiz (45'+2')
- Yusuf Sari (71' Pen)
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.
The Turks, already qualified for Euro 2024, looked sharp but the hosts eased off after a strong start and the result will do little to fuel local fans' expectations for the tournament next year.
"We should have finished off the game in the first 10 minutes," Nagelsmann said. "But from the 25th minute and until the break we did not do much.
"We have to keep playing on the same level, every player has to do it. Then that quality will come through in the games."
Sane came close to scoring himself when he saw Turkey keeper Altay Bayindir out of position but his low drive sailed narrowly wide.
The visitors made the most of a string of defensive errors to hit back. Turkey cut the deficit through Ferdi Kadioglu's powerful shot after he latched on to a deep cross from Abdulkerim Bardakci in the 38th minute.
Niclas Füllkrug 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 but the Turks refused to settle for a draw.
Salih Ozcan hit the post and they earned a 70th-minute penalty for a handball by Havertz which Yusuf Sari converted.
Germany face Austria on Tuesday in another friendly.
- Bartosz Frankowski