Stadium: Court 3 Round: 26 Ground: Clay
| Saarlouis, Singles Qualifying M-ITF-GER-07A | 2023/06/21 17:05 | Asrawy, Amr v Lodewijk Weststrate | 5-7,1-6 |
| Saarlouis, Singles Qualifying M-ITF-GER-07A | 2023/06/19 09:30 | Jurriaan Bol v Lodewijk Weststrate | 0-6,5-7 |
| Saarlouis, Singles Qualifying M-ITF-GER-07A | 2023/06/18 09:00 | Johann, Lars v Lodewijk Weststrate | 4-6,2-6 |
| ITF M15 Duffel | 2023/06/12 10:00 | Adrian Oetzbach v Lodewijk Weststrate | 7-5,1-6,12-10 |
| ITF M15 Duffel | 2023/06/11 11:00 | Aaron James Williams v Lodewijk Weststrate | 2-6,7-6,5-10 |
| ITF M15 Vejle | 2022/07/27 09:40 | Christian Sigsgaard v Lodewijk Weststrate | 6-7,6-1,6-4 |
| ITF M15 Vejle | 2022/07/25 14:55 | Stijn Slump v Lodewijk Weststrate | 2-6,3-6 |
| ITF M25 Den Haag | 2022/06/29 17:50 | Lodewijk Weststrate v Dax Donders | 4-6,6-7 |
| Saarlouis, Singles Qualifying M-ITF-GER-07A | 2023/06/21 13:20 | David Fix v Guy Den Heijer | 6-4,6-7,2-6 |
| Saarlouis, Singles Qualifying M-ITF-GER-07A | 2023/06/19 09:30 | Max Wiskandt v Guy Den Heijer | 4-6,2-6 |
| Saarlouis, Singles Qualifying M-ITF-GER-07A | 2023/06/18 09:00 | Tanner, Gian Luca v Guy Den Heijer | 6-3,2-6,8-10 |
| UTR Pro Hilversum | 2023/06/06 06:00 | Guy Den Heijer v Sklenka, Victor | 7-6,4-6,5-3 |
| UTR Pro Hilversum | 2023/06/05 07:30 | Guy Den Heijer v Ivan Sergeyev | 0-6,2-6 |
| ITF - M15 Antalya | 2023/04/30 07:00 | Guy Den Heijer v Juan Manuel La Serna | 6-7,1-6 |
| ITF - M15 Antalya | 2023/04/02 07:00 | Guy Den Heijer v Niels Visker | 1-6,6-4,3-10 |
| ITF M25 Portimao | 2023/03/14 11:00 | Guy Den Heijer v Mikel Martinez | 1-6,2-6 |