Stadium: Court 1 Round: 25 Ground: Clay
| ITF M15 St Petersburg | 2021/04/07 09:55 | Illya Beloborodko v Constantin Bittoun Kouzmine | 6-3,6-1 |
| ITF M15 Novomoskovsk | 2020/08/31 07:00 | Illya Beloborodko v Constantin Bittoun Kouzmine | 6-2,6-2 |
| Challenger Kyiv | 2021/09/07 11:15 | Sebastian Baez v Illya Beloborodko | 6-3,7-5 |
| ITF M15 Chornomorsk | 2021/09/05 08:00 | Ilya Snitari v Illya Beloborodko | 6-7,6-7 |
| ITF M15 Chornomorsk | 2021/09/04 07:00 | Illya Beloborodko v Yan Bondarevskiy | 3-6,6-4,6-3 |
| ITF M15 Chornomorsk | 2021/09/03 09:10 | Artem Podorozhnyi v Illya Beloborodko | 1-6,6-7 |
| ITF M15 Chornomorsk | 2021/09/02 08:30 | Illya Beloborodko v Clement Tabur | 5-7,6-3,6-0 |
| ITF M15 Chornomorsk | 2021/09/01 09:35 | Lev Levyatov v Illya Beloborodko | 2-6,1-6 |
| ITF M15 Gdynia | 2021/08/10 08:00 | Illya Beloborodko v Antonin Bolardt | 6-7,1-6 |
| ITF M15 Gdynia | 2021/08/09 08:00 | Illya Beloborodko v Alexander Wolfschmidt | 6-1,6-2 |
| ITF M15 Sozopol | 2021/09/14 10:00 | Valentin Vacherot v Constantin Bittoun Kouzmine | 6-3,5-7,6-4 |
| ITF M15 Zilina | 2021/09/02 10:55 | Constantin Bittoun Kouzmine v Fabian Marozsan | 6-7,4-6 |
| ITF M15 Zilina | 2021/09/01 09:55 | Kristof Minarik v Constantin Bittoun Kouzmine | 4-6,2-6 |
| ITF M25 Ueberlingen | 2021/08/18 14:10 | Milan Welte v Constantin Bittoun Kouzmine | 6-4,6-0 |
| ITF M15 Cairo | 2021/08/05 09:20 | Lukas Krainer v Constantin Bittoun Kouzmine | 6-1,6-2 |
| ITF M15 Cairo | 2021/08/04 07:30 | Gabriele Maria Noce v Constantin Bittoun Kouzmine | 0-6,6-3,4-6 |
| ITF M15 Cairo | 2021/08/03 07:30 | Constantin Bittoun Kouzmine v Thiago Cigarran | 6-1,4-6,10-8 |
| ITF M15 Cairo | 2021/08/02 08:30 | Constantin Bittoun Kouzmine v Tobias Franco | 6-2,6-0 |