Stadium: Court 3 Round: 26 Ground: Clay
| ITF M15 Cairo | 2021/11/24 08:00 | Duckhee Lee v Luca Tomasetto | 6-3,5-7,6-4 |
| ITF M15 Sharm El Sheikh | 2021/11/20 08:00 | Peter Fajta v Duckhee Lee | 6-3,6-4 |
| ITF M15 Sharm El Sheikh | 2021/11/19 08:00 | Chien Hsun Lo v Duckhee Lee | 2-6,1-6 |
| ITF M15 Sharm El Sheikh | 2021/11/18 09:50 | Neil Oberleitner v Duckhee Lee | 3-6,4-6 |
| ITF M15 Sharm El Sheikh | 2021/11/17 12:50 | Erik Arutiunian v Duckhee Lee | 2-6,0-6 |
| ITF M15 Sharm El Sheikh | 2021/11/10 12:50 | Daniel Little v Duckhee Lee | 7-6,7-6 |
| Challenger Columbus | 2021/09/19 20:15 | Duckhee Lee v Evan Song | 3-6,6-7 |
| ITF M15 Monastir | 2021/06/30 10:35 | Omni Kumar v Duckhee Lee | 6-0,6-2 |
| ITF M15 Cairo | 2021/11/24 07:55 | Daniil Ostapenkov v Tsung-Hao Huang | 6-1,6-0 |
| ITF M15 Sharm El Sheikh | 2021/11/10 14:05 | Saba Purtseladze v Daniil Ostapenkov | 7-6,6-3 |
| ITF M15 Sharm El Sheikh | 2021/11/03 08:00 | Daniil Ostapenkov v Emiliano Maggioli | 6-3,1-6,2-6 |
| ITF M15 Sharm El Sheikh | 2021/10/27 08:00 | Karim-Mohamed Maamoun v Daniil Ostapenkov | 7-6,6-0 |
| Davis Cup | 2021/09/19 17:40 | Federico Coria v Daniil Ostapenkov | 6-3,6-1 |
| Davis Cup | 2021/09/18 14:00 | Diego Schwartzman v Daniil Ostapenkov | 4-6,3-6 |
| Davis Cup | 2020/03/07 14:30 | Dominik Koepfer v Daniil Ostapenkov | 6-0,6-2 |