Stadium: Centre Court Round: 25 Ground: Clay
| ITF M25 Bolzano | 2021/08/03 16:15 | Emiliano Maggioli v Kirill Kivattsev | 1-6,6-4,6-4 |
| ITF M15 Esch/Alzette | 2021/07/20 15:50 | Kirill Kivattsev v Mick Veldheer | 4-6,3-6 |
| ITF M25 Telfs | 2021/07/18 13:20 | Filip Misolic v Kirill Kivattsev | 6-2,6-4 |
| ITF M25 Telfs | 2021/07/18 08:00 | Kirill Kivattsev v Alex M Pujolras | 6-3,6-1 |
| ITF M25 Telfs | 2021/07/16 10:00 | Kirill Kivattsev v Ondrej Horak | 6-2,6-2 |
| ITF M25 Telfs | 2021/07/13 09:00 | Danylo Kalenichenko v Kirill Kivattsev | 4-6,3-6 |
| ITF M25 Marburg | 2021/07/05 09:30 | Kirill Kivattsev v Andres Gabriel Ciurletti | 6-7,6-7 |
| ITF M15 Bergamo | 2021/06/22 11:40 | Federico Arnaboldi v Kirill Kivattsev | 6-4,6-2 |
| ITF M25 Koksijde | 2021/08/16 08:00 | Victor Ernaelsteen v John Sperle | 3-6,3-6 |
| ITF M25 Wetzlar | 2021/08/03 15:30 | John Sperle v Osman Torski | 3-6,3-6 |
| UTR Pro Tennis Series Mulheim | 2021/07/30 13:30 | Hazem Naw v John Sperle | 6-4,6-2 |
| UTR Pro Tennis Series Mulheim | 2021/07/30 07:00 | Hendrik Jebens v John Sperle | 4-6,6-7 |
| UTR Pro Tennis Series Mulheim | 2021/07/29 08:30 | Marvin Schaber v John Sperle | 2-6,2-6 |
| UTR Pro Tennis Series Mulheim | 2021/07/28 12:00 | Tim Gennes v John Sperle | 1-6,3-6 |
| UTR Pro Tennis Series Mulheim | 2021/07/26 12:30 | Vasile Antonescu v John Sperle | 6-3,5-2 |
| ITF M15 Antalya | 2021/05/31 08:30 | Daniel Antonio Nunez v John Sperle | 6-4,7-5 |