Stadium: Court 4 Round: 27 Ground: Hardcourt outdoor
| ITF M25 Pretoria | 2021/09/30 07:30 | Ryan Nijboer v Devin Badenhorst | 6-3,5-7,6-3 |
| ITF M25 Pretoria | 2021/09/29 12:20 | Ryan Nijboer v Menelaos Efstathiou | 6-3,6-0 |
| ITF M25 Johannesburg | 2021/09/21 10:25 | Rio Noguchi v Ryan Nijboer | 7-6,2-6,6-3 |
| ITF M25 Johannesburg | 2021/09/15 08:00 | Alafia Ayeni v Ryan Nijboer | 7-5,6-3 |
| ITF M25 Trier | 2021/08/27 15:00 | Ryan Nijboer v Henri Squire | 2-6,3-6 |
| ITF M25 Trier | 2021/08/26 09:30 | Constantin Schmitz v Ryan Nijboer | 4-6,2-6 |
| ITF M25 Trier | 2021/08/25 09:00 | Tom Gentzsch v Ryan Nijboer | 3-6,4-6 |
| ITF M15 Oldenzaal | 2021/08/19 12:45 | Alexander Hoogmartens v Ryan Nijboer | 1-6,7-5,6-3 |
| ITF M25 Pretoria | 2021/09/30 07:30 | Dylan Salton v Michail Pervolarakis | 2-6,0-6 |
| ITF M25 Pretoria | 2021/09/29 11:30 | Markos Kalovelonis v Michail Pervolarakis | 3-6,2-6 |
| ITF M25 Johannesburg | 2021/09/26 09:30 | Alastair Gray v Michail Pervolarakis | 4-6,6-3,6-2 |
| ITF M25 Johannesburg | 2021/09/25 08:00 | Michail Pervolarakis v Benjamin Lock | 6-4,7-6 |
| ITF M25 Johannesburg | 2021/09/24 10:05 | Rio Noguchi v Michail Pervolarakis | 4-6,2-6 |
| ITF M25 Johannesburg | 2021/09/22 09:05 | Connor H Van Schalkwyk v Michail Pervolarakis | 6-4,1-6,2-6 |
| Davis Cup | 2021/09/18 10:35 | Michail Pervolarakis v Laurynas Grigelis | 6-7,6-3,5-7 |
| UTR Pro Tennis Series California | 2021/09/03 15:00 | Michail Pervolarakis v Drew Baird | 6-4,3-6,5-7 |