Stadium: Court 5 Round: 14 Ground: Clay
| ITF M25 Marburg | 2021/07/08 10:35 | Louis Wessels v Alexander Donski | 6-4,6-7,6-4 |
| ITF M25 Marburg | 2021/07/06 16:40 | Alexander Donski v Jeremy Jahn | 6-2,6-2 |
| ITF M15 Monastir | 2021/06/23 08:30 | Alexander Donski v Omni Kumar | 1-6,3-6 |
| ITF M15 Monastir | 2021/06/17 11:40 | Alexander Donski v Luca Giacomini | 3-6,3-6 |
| ITF M15 Monastir | 2021/06/15 08:30 | Lucio Carnevalle v Alexander Donski | 2-6,3-6 |
| ITF M15 Heraklion | 2021/06/10 07:30 | Alexander Donski v Yuki Mochizuki | 3-6,4-6 |
| ITF M15 Heraklion | 2021/06/09 11:50 | Alexander Donski v Daniel Little | 1-6,6-3,6-1 |
| ITF M15 Heraklion | 2021/06/03 06:30 | Alexander Donski v Reese Stalder | 3-6,6-3,4-6 |
| ITF M25 Prostejov | 2021/08/21 07:50 | Facundo Diaz Acosta v Nikolas Sanchez Izquierdo | 4-6,6-1,4-6 |
| ITF M25 Prostejov | 2021/08/20 10:00 | Facundo Diaz Acosta v Dalibor Svrcina | 6-3,6-3 |
| ITF M25 Prostejov | 2021/08/19 11:15 | Lucas Miedler v Facundo Diaz Acosta | 1-6,2-6 |
| ITF M25 Prostejov | 2021/08/18 09:45 | Jiri Jenicek v Facundo Diaz Acosta | 0-6,0-6 |
| ITF M25 Prostejov | 2021/08/17 10:30 | Victor Sklenka v Facundo Diaz Acosta | 0-6,0-6 |
| Challenger Prague | 2021/08/09 09:55 | Adrian Andreev v Facundo Diaz Acosta | 2-6,6-4,6-3 |
| Challenger Prague | 2021/08/08 12:00 | Facundo Diaz Acosta v Matija Pecotic | 7-6,6-1 |
| ITF M25 Grodzisk Mazowiecki | 2021/08/05 14:40 | Facundo Diaz Acosta v Maciej Rajski | 6-4,1-6,4-6 |