Stadium: Hard 17 Round: 44 Ground: Hardcourt outdoor
| 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 Beograd | 2023/10/12 07:30 | Aleksa Mardjonovic v Gabriel Matuszewski | 0-3 |
| UTR Pro Beograd | 2023/10/10 12:58 | Gabriel Matuszewski v Drazen Petrovic | 6-3,6-4 |
| UTR Pro Beograd | 2023/10/08 09:00 | Gabriel Matuszewski v Vuk Radjenovic | 2-6,5-7 |
| UTR Pro Beograd | 2023/10/07 08:07 | Gabriel Matuszewski v Tadija Radovanovic | 5-7,6-4,5-7 |
| UTR Pro Beograd | 2023/10/05 06:00 | Luka Todorovic v Gabriel Matuszewski | 0-0 |
| UTR Pro Beograd | 2023/10/04 06:00 | Gabriel Matuszewski v Illya Beloborodko | 0-6,6-1,4-6 |
| ITF M15 Heraklion | 2023/10/15 07:00 | Stefan Cizelj-Zivkovic v Graham Maassen | 3-6,3-6 |
| ITF M15 Kursumlijska Banja | 2023/09/17 08:30 | Stefan Cizelj-Zivkovic v Jerko Brkic | 3-6,6-4,8-10 |
| ITF M15 Kursumlijska Banja | 2023/09/10 09:30 | Alexandar Balj v Stefan Cizelj-Zivkovic | 6-2,6-2 |
| ITF M15 Madrid | 2023/09/05 10:00 | Stefan Cizelj-Zivkovic v Luis Francisco | 3-6,2-6 |
| ITF M15 Madrid | 2023/09/04 07:30 | Stefan Cizelj-Zivkovic v Cian Maguire | 6-3,6-7,10-6 |
| ITF M15 Madrid | 2023/09/03 12:00 | Tommaso Carnevale-Miino v Stefan Cizelj-Zivkovic | 6-7,2-6 |
| ITF M25 Gandia | 2023/07/17 10:00 | Patricio Alvarado v Stefan Cizelj-Zivkovic | 6-4,6-2 |
| ITF M15 Kursumlijska Banja | 2023/06/14 10:20 | Stefan Cizelj-Zivkovic v Dusan Obradovic | 4-6,1-6 |