| UTR Pro Tennis Series Zadar | 2021/09/30 09:30 | Christos Keisidis v Stefanos Sakellaridis | 4-6,6-4,6-4 |
| UTR Pro Tennis Series Zadar | 2021/09/29 08:00 | Duje Kekez v Christos Keisidis | 6-2,2-6,5-6 |
| UTR Pro Tennis Series Zadar | 2021/09/28 12:30 | Janos Fekete v Christos Keisidis | 6-4,5-3 |
| UTR Pro Tennis Series Mulheim | 2021/09/25 10:30 | Christos Keisidis v Lawrence Bataljin | 6-4,5-3 |
| UTR Pro Tennis Series Mulheim | 2021/09/24 08:00 | Christos Keisidis v Jurriaan Bol | 1-6,4-6 |
| UTR Pro Tennis Series Mulheim | 2021/09/23 11:00 | Christos Keisidis v Artem Podorozhnyi | 5-7,2-5 |
| UTR Pro Tennis Series Mulheim | 2021/09/22 14:00 | Colin Sinclair v Christos Keisidis | 6-3,6-1 |
| UTR Pro Tennis Series Mulheim | 2021/09/21 08:00 | Edison Ambarzumjan v Christos Keisidis | 6-2,4-6,5-1 |
| UTR Pro Tennis Series Zadar | 2021/09/30 09:30 | Duje Kekez v Drazen Petrovic | 3-6,4-5 |
| UTR Pro Tennis Series Zadar | 2021/09/29 08:00 | Janos Fekete v Drazen Petrovic | 4-6,6-4,1-6 |
| UTR Pro Tennis Series Zadar | 2021/09/27 11:30 | Stefanos Sakellaridis v Drazen Petrovic | 7-6,2-6,5-2 |
| ITF M15 Ulcinj | 2021/09/19 08:00 | Drazen Petrovic v Ervin H Eminefendic | 3-6,7-6,6-10 |
| ITF M15 Ulcinj | 2021/09/14 07:55 | Drazen Petrovic v Rimpei Kawakami | 1-6,3-6 |
| Challenger Banja Luka | 2021/09/06 14:30 | Drazen Petrovic v Carlos Gomez-Herrera | 1-6,0-6 |
| ITF M15 Novi Sad | 2021/08/03 09:40 | Aleksandar Tomas v Drazen Petrovic | 6-7,6-0,10-8 |
| ITF M15 Novi Sad | 2021/08/02 08:00 | Drazen Petrovic v Darko Jandric | 6-4,6-0 |