Round: 25 Ground: Clay
| ITF Czech Republic F4 | 2017/07/05 08:00 | Dennis Novak v Peter Heller | 6-3,6-1 |
| ITF Czech Republic F4 | 2017/07/04 10:00 | Peter Heller v Vitaliy Sachko | 6-2,6-3 |
| ITF Germany F5 | 2017/06/29 09:00 | Peter Heller v Peter Torebko | 4-6,2-6 |
| ITF Germany F5 | 2017/06/27 12:40 | Valentin Guenther v Peter Heller | 1-6,4-6 |
| ITF Poland F1 | 2017/06/16 14:55 | Kamil Majchrzak v Peter Heller | 6-3,7-6 |
| ITF Poland F1 | 2017/06/14 09:00 | Robin Stanek v Peter Heller | 3-6,4-6 |
| ITF Poland F1 | 2017/06/12 12:00 | Peter Heller v Jonas Luetjen | 2-6,7-5,6-3 |
| ITF Italy F16 | 2017/06/08 13:00 | Peter Heller v Andrea Collarini | 2-6,4-6 |
| ITF Austria F3 | 2017/07/16 11:25 | Edward Hubner v Kai Lemstra | 1-6,3-6 |
| ITF Austria F3 | 2017/07/15 13:30 | Neil Oberleitner v Kai Lemstra | 1-6,0-6 |
| ITF Germany F15 | 2016/10/19 12:30 | Kai Lemstra v Alexandar Lazarov | 3-6,4-6 |
| ITF Germany F14 | 2016/10/10 10:00 | Lukas Ollert v Kai Lemstra | 7-5,6-2 |
| ITF Germany F14 | 2016/10/09 07:00 | Sven Lemstra v Kai Lemstra | 1-6,2-6 |
| ITF Germany F13 | 2016/10/06 12:00 | Kai Lemstra v Marek Jaloviec | 4-6,2-6 |
| ITF Germany F13 | 2016/10/05 12:00 | Kai Lemstra v Leon Hoeveler | 7-5,6-3 |
| ITF Germany F17 | 2015/10/18 07:00 | Kai Lemstra v Jakob Schnaitter | 4-6,3-6 |