Stadium: Court 3 Round: 25 Ground: Clay
| ATP Umag | 2019/07/14 08:00 | Salvatore Caruso v Nik Razborsek | 6-3,6-2 |
| ITF M15 Den Haag | 2019/07/04 09:05 | Nik Razborsek v Geoffrey Blancaneaux | 5-7,0-6 |
| ITF M15 Den Haag | 2019/07/02 15:05 | Nik Razborsek v Jay Zwinkels | 6-0,6-0 |
| ITF M15 Kamen | 2019/06/27 11:40 | Nik Razborsek v Riccardo Maiga | 5-7,6-7 |
| ITF M15 Kamen | 2019/06/25 10:40 | Nik Razborsek v Henri Squire | 6-2,2-6,6-2 |
| ITF M15 Kaltenkirchen | 2019/06/11 13:50 | Nik Razborsek v Damien Wenger | 6-4,1-6,1-6 |
| ITF M25 Kiseljak | 2019/06/02 07:00 | Martins Podzus v Nik Razborsek | 7-5,6-3 |
| ITF M25 Kiseljak | 2019/05/30 12:10 | Frane Nincevic v Nik Razborsek | 3-6,3-6 |
| 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 |
| ITF M15 Kramsach | 2019/07/15 13:30 | Kai Lemstra v Evzen Holis | 6-3,4-6,10-6 |
| ITF M15 Troisdorf | 2019/05/06 14:00 | Mick Veldheer v Kai Lemstra | 2-6,6-1,10-7 |
| ITF M15 Sharm El Sheikh | 2019/03/21 08:00 | Enrico Dalla Valle v Kai Lemstra | 6-1,6-1 |
| ITF M15 Sharm El Sheikh | 2019/03/20 09:40 | Stefan Palosi v Kai Lemstra | 4-6,2-6 |
| ITF M15 Sharm El Sheikh | 2019/03/18 12:30 | Fabrizio Andaloro v Kai Lemstra | 2-6,2-6 |