Round: 44 Ground: Hardcourt outdoor
| ITF M25 Santa Margherita | 2019/10/07 12:00 | Daniel Kossek v Alexander Mannapov | 4-6,1-6 |
| ITF M25 Santa Margherita | 2019/10/06 09:00 | Luigi Castelletti v Daniel Kossek | 6-2,5-7,4-10 |
| ITF M25 Bydgoszcz | 2019/08/12 08:00 | Petr Michnev v Daniel Kossek | 6-1,6-2 |
| ITF M15 Koszalin | 2019/08/06 08:00 | Egor Noskin v Daniel Kossek | 6-3,6-1 |
| ITF M15 Koszalin | 2019/08/05 08:00 | Daniel Kossek v Mikolaj Borkowski | 6-7,6-2,10-8 |
| ITF M15 Antalya | 2019/05/20 07:45 | Daniil Gusev v Daniel Kossek | 6-4,6-1 |
| ITF M15 Antalya | 2019/05/13 07:45 | Daniel Kossek v Sergei Pogosian | 3-6,3-6 |
| ITF M15 Cancun | 2019/03/27 14:00 | Daniel Kossek v Lucas Gomez | 0-6,3-6 |
| ITF M15 Bad Salzdetfurth | 2019/10/08 09:00 | Kai Lemstra v Christopher Patzanovsky | 6-7,4-6 |
| ITF M15 Ueberlingen | 2019/08/21 09:55 | Peter Heller v Kai Lemstra | 5-7,6-2,6-2 |
| ITF M15 Trier | 2019/08/13 11:05 | Kai Lemstra v Jordi Walder | 4-6,2-6 |
| Challenger Augsburg | 2019/08/05 12:25 | Facundo Mena v Kai Lemstra | 6-4,6-2 |
| ITF M15 Bad Schussenried | 2019/07/23 14:35 | Nik Razborsek v Kai Lemstra | 6-2,6-3 |
| ITF M15 Bad Schussenried | 2019/07/22 13:00 | Roy Sarut De Valk v Kai Lemstra | 5-7,4-6 |
| ITF M15 Bad Schussenried | 2019/07/22 08:00 | Giordan Kunz v Kai Lemstra | 1-6,1-6 |
| ITF M15 Kramsach | 2019/07/17 09:00 | Kai Lemstra v Bart Van Den Berg | 4-6,2-6 |