| UTR Pro Tennis Series Florida | 2021/12/15 18:45 | Connor Krug v Alexander Kotzen | 6-3,3-6,2-6 |
| UTR Pro Tennis Series Florida | 2021/12/14 14:00 | Martim L Prata v Alexander Kotzen | 7-6,3-6,5-7 |
| ITF M15 Champaign | 2021/09/16 15:00 | Alexander Kotzen v Cannon Kingsley | 4-6,3-6 |
| ITF M15 Champaign | 2021/09/15 19:50 | Alexander Kotzen v Lucas Horve | 6-2,6-3 |
| ITF M25 Koksijde | 2021/08/17 08:00 | Olivier Rojas v Alexander Kotzen | 6-4,6-3 |
| ITF M15 Gdynia | 2021/08/10 08:00 | Alexander Kotzen v Olaf Pieczkowski | 2-6,6-2,8-10 |
| ITF M15 Gdynia | 2021/08/09 08:00 | Alexander Kotzen v Piotr Pawlak | 6-2,6-0 |
| ITF M15 Parnu | 2021/08/05 10:30 | Ergi Kirkin v Alexander Kotzen | 7-6,6-4 |
| UTR Pro Tennis Series Florida | 2021/12/14 14:00 | Connor Krug v Oskar Brostrom Poulsen | 7-5,6-7,5-1 |
| UTR Pro Tennis Series Florida | 2021/12/13 19:30 | Oskar Brostrom Poulsen v Francois Musitelli | 2-6,3-6 |
| UTR Pro Tennis Series Copenhagen | 2021/06/15 09:30 | Alejandro Mendoza v Oskar Brostrom Poulsen | 5-2 |
| UTR Pro Tennis Series Copenhagen | 2021/06/14 11:00 | Oskar Brostrom Poulsen v Jesper Klov Nilsson | 3-6,3-6 |