Stadium: Court 18 Round: 25 Ground: Clay
| ITF Germany F13 | 2018/08/20 09:00 | Kai Lemstra v Walder, Jordi | 3-6,6-1,3-6 |
| Augsbourg, Allemagne | 2019/08/05 12:25 | Facundo Mena v Kai Lemstra | 6-4,6-2 |
| Bad Schussenried, Singles Qualifying M-ITF-GER-10A | 2019/07/23 14:35 | Nik Razborsek v Kai Lemstra | 6-2,6-3 |
| Bad Schussenried, Singles Qualifying M-ITF-GER-10A | 2019/07/22 13:00 | de Valk, Roy Sarut v Kai Lemstra | 5-7,4-6 |
| Bad Schussenried, Singles Qualifying M-ITF-GER-10A | 2019/07/22 08:00 | Kunz, Giordan v Kai Lemstra | 1-6,1-6 |
| Kramsach, Singles M-ITF-AUT-02A | 2019/07/17 09:00 | Kai Lemstra v van Den Berg, Bart | 4-6,2-6 |
| Kramsach, Singles M-ITF-AUT-02A | 2019/07/15 13:30 | Kai Lemstra v Holis, Evzen | 6-3,4-6,10-6 |
| ITF M15 Troisdorf | 2019/05/06 14:00 | Veldheer, Mick 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 Marburg | 2019/07/08 08:00 | Heger, Tim v Walder, Jordi | 3-6,7-5,10-7 |
| ITF M15 Kamen | 2019/06/26 09:00 | Prechtel, Sebastian v Walder, Jordi | 6-4,3-6,6-3 |
| ITF M15 Kamen | 2019/06/24 12:30 | Ewan Moore v Walder, Jordi | 6-4,3-6,6-10 |
| ITF M15 Kamen | 2019/06/24 08:00 | Litvinov, Daniel v Walder, Jordi | 1-6,2-6 |
| Kaltenkirchen, Singles Qualifying M-ITF-GER-05A | 2019/06/10 08:00 | Paul Woerner v Walder, Jordi | 6-3,6-3 |
| ITF M15 Troisdorf | 2019/05/06 10:00 | Kacper Zuk v Walder, Jordi | 6-0,6-3 |
| ITF M15 Troisdorf | 2019/05/06 07:00 | Strelchenko, Daniil v Walder, Jordi | 2-6,1-6 |
| ITF - M15 Antalya | 2019/04/29 06:45 | Walder, Jordi v Michalis Sakellaridis | 3-6,3-6 |