Stadium: Court 1 Oberhaching Round: 44 Ground: Hardcourt indoor
| ITF Germany F9 | 2018/07/24 14:45 | Kai Lemstra v Christoph Negritu | 2-6,4-6 |
| ITF M25 Karlsruhe | 2019/06/06 10:00 | Christoph Negritu v Andrea Pellegrino | 2-6,0-6 |
| ITF M25 Karlsruhe | 2019/06/05 09:00 | Facundo Diaz Acosta v Christoph Negritu | 1-6,3-6 |
| ITF M25 Karlsruhe | 2019/06/04 10:25 | Christoph Negritu v Adrian Oetzbach | 7-5,6-7,7-10 |
| ITF M25 Karlsruhe | 2019/06/03 09:00 | Christoph Negritu v Niklas Schell | 6-2,2-6,10-7 |
| ITF M15 Troisdorf | 2019/05/07 12:05 | Christoph Negritu v Kacper Zuk | 1-6,3-6 |
| ITF M15 Grasse | 2019/04/30 13:25 | Clement Tabur v Christoph Negritu | 6-4,6-2 |
| ITF M25 Angers | 2019/04/25 16:10 | Tobias Simon v Christoph Negritu | 6-4,6-7,6-0 |
| ITF M25 Angers | 2019/04/24 11:10 | Christoph Negritu v Maxime Pauwels | 6-2,6-4 |
| ITF M15 Oberhaching | 2020/02/16 10:30 | Kai Lemstra v Dominik Langmajer | 6-1,6-0 |
| ITF M25 Barnstaple | 2020/02/09 14:30 | Kai Lemstra v Henry Patten | 5-7,2-6 |
| ITF M15 Sharm El Sheikh | 2019/11/14 08:00 | Vladyslav Manafov v Kai Lemstra | 6-1,6-2 |
| ITF M15 Sharm El Sheikh | 2019/11/13 08:00 | Tsung-Hao Huang v Kai Lemstra | 6-7,2-6 |
| ITF M15 Sharm El Sheikh | 2019/11/05 08:00 | Kalman Boyd v Kai Lemstra | 7-5,6-4 |
| ITF M15 Sharm El Sheikh | 2019/11/04 08:00 | Martin Dobry v Kai Lemstra | 3-6,3-6 |
| ITF M15 Sharm El Sheikh | 2019/10/29 08:00 | Timur Kiyamov v Kai Lemstra | 6-3,7-6 |
| ITF M15 Sharm El Sheikh | 2019/10/28 09:00 | Daniel Kossek v Kai Lemstra | 1-6,1-6 |