Stadium: Court 2 Round: 44 Ground: Clay
| ITF M15 Sarajevo | 2021/06/02 10:30 | Dusan Trunic v Simon Beaupain | 2-6,4-6 |
| ITF M15 Novi Sad | 2021/08/03 10:10 | Aleksa Mardjonovic v Valerio Aboian | 2-6,7-5,10-12 |
| ITF M15 Novi Sad | 2021/08/02 09:30 | Hamid Reza Nadaf v Aleksa Mardjonovic | 3-6,7-5,5-10 |
| ITF M15 Novi Sad | 2021/08/01 10:45 | Michalis Sakellaridis v Aleksa Mardjonovic | 2-6,2-6 |
| ITF M15 Novi Sad | 2021/07/26 10:30 | Roman Andres Burruchaga v Aleksa Mardjonovic | 6-3,7-6 |
| ITF M15 Novi Sad | 2021/07/25 12:00 | Aleksa Mardjonovic v Berk Ilkel | 6-2,7-5 |
| UTR Pro Tennis Series Beograd | 2021/07/11 07:00 | Stefan Milicevic v Aleksa Mardjonovic | 6-4,6-2 |
| UTR Pro Tennis Series Beograd | 2021/07/10 10:00 | Petar Teodorovic v Aleksa Mardjonovic | 2-6,6-4,3-6 |
| UTR Pro Tennis Series Beograd | 2021/07/09 10:00 | Aleksa Mardjonovic v Viktor Jovic | 1-6,1-6 |