Stadium: Court Tsitsipas Round: 62 Ground: Hardcourt outdoor
| UTR Pro Tennis Series Nis | 2021/10/09 08:00 | Aleksa Mardjonovic v Veljko Krstic | 6-3,6-4 |
| UTR Pro Tennis Series Nis | 2021/10/08 14:15 | Stefan Ivic v Veljko Krstic | 6-4,3-6,1-5 |
| UTR Pro Tennis Series Nis | 2021/10/07 08:30 | Lawrence Bataljin v Veljko Krstic | 7-6,3-6,5-7 |
| UTR Pro Tennis Series Nis | 2021/10/05 09:30 | Ivan Liutarevich v Veljko Krstic | 5-7,6-4,6-2 |
| UTR Pro Tennis Series Nis | 2021/10/04 08:30 | Veljko Krstic v Oleksandr Bielinskyi | 5-7,6-1,6-3 |
| ITF M15 Zlatibor | 2021/09/16 09:40 | Oleksandr Ovcharenko v Veljko Krstic | 6-1,6-1 |
| ITF M15 Zlatibor | 2021/09/14 11:10 | Tomislav Jotovski v Veljko Krstic | 4-6,1-6 |
| ITF M25 Belgrade | 2021/06/29 10:40 | Skander Mansouri v Veljko Krstic | 7-6,7-5 |
| ITF M15 Heraklion | 2021/10/31 08:00 | Alessandro Spadola v Tiran Sanghera | 6-2,6-4 |
| ITF M15 L'Aquila | 2021/07/11 07:00 | Gianmarco Ferrari v Alessandro Spadola | 6-0,6-0 |