Stadium: Court 15 Round: 44 Ground: Hardcourt outdoor
| ITF M15 - Heraklion | 2023/10/25 08:55 | Mario G Fernandez v Guy Den Heijer | 6-1,6-3 |
| ITF M15 - Heraklion | 2023/10/24 06:30 | Guy Den Heijer v Joshua Charlton | 7-6,7-5 |
| ITF M15 - Heraklion | 2023/10/23 10:30 | Guy Den Heijer v Vojtech Mares | 5-7,7-6,10-6 |
| ITF M15 - Heraklion | 2023/10/19 08:45 | Guy Den Heijer v Gabriel Decamps | 2-6,4-6 |
| ITF M25 - Santa Margherita | 2023/09/25 08:00 | Niels Visker v Guy Den Heijer | 5-7,6-4,11-9 |
| ITF M25 - Santa Margherita | 2023/09/24 08:00 | Niccolo Ciavarella v Guy Den Heijer | 6-2,3-6,7-10 |
| ITF M25 - Santa Margherita | 2023/09/18 08:30 | Guy Den Heijer v Toby Martin | 5-7,6-3,7-10 |
| ITF M15 - Haren | 2023/09/07 17:25 | Guy Den Heijer v Adrian Oetzbach | 6-7,6-7 |
| ITF M25 - Heraklion | 2023/10/29 10:30 | Gianluca Carlini v Gabriel Matuszewski | 6-7,1-6 |
| ITF M15 - Heraklion | 2023/10/22 08:30 | Gabriel Matuszewski v Stefan Cizelj-Zivkovic | 4-6,4-6 |
| ITF M15 - Heraklion | 2023/10/17 06:30 | Ioannis Kountourakis v Gabriel Matuszewski | 6-3,6-0 |
| ITF M15 - Heraklion | 2023/10/16 09:00 | Gianluca Carlini v Gabriel Matuszewski | 6-4,1-6,5-10 |
| UTR Pro - Belgrad | 2023/10/12 07:30 | Aleksa Mardjonovic v Gabriel Matuszewski | 0-3 |
| UTR Pro - Belgrad | 2023/10/10 12:58 | Gabriel Matuszewski v Drazen Petrovic | 6-3,6-4 |
| UTR Pro - Belgrad | 2023/10/08 09:00 | Gabriel Matuszewski v Vuk Radjenovic | 2-6,5-7 |
| UTR Pro - Belgrad | 2023/10/07 08:07 | Gabriel Matuszewski v Tadija Radovanovic | 5-7,6-4,5-7 |