Stadium: Court 1 Round: 25 Ground: Hardcourt indoor
| ITF M25 Nevers | 2021/10/04 09:00 | Constantin Bittoun Kouzmine v Hendrik Jebens | 6-3,6-2 |
| ITF M15 Vyshkovo | 2021/09/22 12:45 | Illya Beloborodko v Constantin Bittoun Kouzmine | 7-6,6-4 |
| 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 M25 Nevers | 2021/10/04 14:20 | Martin Breysach v Leo Doukhan | 6-3,6-4 |
| ITF M15 Forbach | 2021/09/28 13:00 | Max Hans Rehberg v Martin Breysach | 6-2,6-0 |
| ITF M15 Monastir | 2021/09/15 09:30 | Martin Breysach v Amaury Raynel | 2-6,3-6 |
| ITF M15 Monastir | 2021/09/08 08:00 | Martin Breysach v Jeremy Beale | 4-6,2-6 |
| ITF M25 Bagneres-De-Bigorre | 2021/09/01 12:25 | Robin Bertrand v Martin Breysach | 6-3,6-2 |
| ITF M25 Bagneres-De-Bigorre | 2021/08/30 09:40 | Martin Breysach v Matt Ponchet | 6-0,6-1 |
| ITF M15 Castelo Branco | 2021/07/29 08:30 | Martin Breysach v Duarte Vale | 2-6,4-6 |
| ITF M15 Castelo Branco | 2021/07/27 12:10 | Naoki Tajima v Martin Breysach | 6-3,2-6,2-6 |