Stadium: Court 1 Round: 44 Ground: Hardcourt outdoor
| Challenger Nur-Sultan | 2021/07/20 06:05 | Alexey Zakharov v Malek Jaziri | 0-6,2-6 |
| Challenger Nur-Sultan | 2021/07/11 04:00 | Alexey Zakharov v Yan Bondarevskiy | 7-5,4-6,2-6 |
| ITF M15 St Petersburg | 2021/04/16 07:55 | Matic Spec v Alexey Zakharov | 6-2,6-4 |
| ITF M15 St Petersburg | 2021/04/15 09:45 | Constantin Bittoun Kouzmine v Alexey Zakharov | 4-6,4-6 |
| ITF M15 St Petersburg | 2021/04/14 09:55 | Egor Noskin v Alexey Zakharov | 2-6,6-1,2-6 |
| ITF M15 St Petersburg | 2021/04/08 10:45 | Sarp Agabigun v Alexey Zakharov | 6-2,6-4 |
| ITF M15 St Petersburg | 2021/04/07 07:00 | Naoki Tajima v Alexey Zakharov | 3-6,6-1,3-6 |
| ITF M15 Kazan | 2021/03/13 08:00 | Alexey Zakharov v Alibek Kachmazov | 7-5,6-3 |
| ITF M15 Monastir | 2021/06/21 09:00 | Tomas Farjat v Sungbeen Sim | 6-4,6-4 |
| ITF M15 Monastir | 2021/06/20 12:00 | Leonardo Lopez Linquet v Sungbeen Sim | 3-6,1-6 |
| ITF M15 Monastir | 2021/06/07 13:30 | Dong Ju Kim v Sungbeen Sim | 6-0,3-6,10-7 |
| ITF M15 Monastir | 2021/06/07 09:00 | Sungbeen Sim v Luc Koenig | 6-3,6-1 |
| ITF M15 Monastir | 2021/06/06 10:00 | Sungbeen Sim v Pierre Antoine Tailleu | 6-3,7-6 |
| ITF M15 Monastir | 2021/05/31 08:00 | Maxence Beauge v Sungbeen Sim | 7-6,6-2 |
| ITF M15 Monastir | 2021/05/24 08:00 | Sungbeen Sim v Mauro De Maio | 6-4,1-6,8-10 |
| ITF M15 Monastir | 2021/05/17 13:30 | Omni Kumar v Sungbeen Sim | 6-4,7-5 |