| UTR Pro Tennis Series Copenhagen | 2021/10/20 13:15 | Nikolaj Katic v Vilhelm Fridell | 5-7,6-4,1-6 |
| UTR Pro Tennis Series Copenhagen | 2021/10/19 11:30 | Nikolaj Katic v Yurii Dzhavakian | 4-6,4-6 |
| UTR Pro Tennis Series Copenhagen | 2021/10/18 11:30 | Nikolaj Katic v Henrik Heise Korsgaard | 1-6,6-3,6-4 |
| ITF M15 Doha | 2021/10/11 13:30 | Boris Butulija v Nikolaj Katic | 6-1,6-3 |
| ITF M15 Doha Qual | 2021/10/10 15:45 | Theertha Shashank Macherla v Nikolaj Katic | 4-6,6-7 |
| ITF M15 Doha | 2021/10/04 12:00 | Nikolaj Katic v Tao Mu | 0-6,1-6 |
| ITF M15 Doha | 2021/10/03 13:20 | Alexey Dubinin v Nikolaj Katic | 2-6,1-6 |
| ITF M25 Falun | 2021/09/26 11:00 | Nikolaj Katic v Daniel Little | 6-7,4-6 |
| UTR Pro Tennis Series Copenhagen | 2021/10/20 07:00 | Henrik Heise Korsgaard v Felipe Mikkelsen | 6-1,3-6,5-3 |
| UTR Pro Tennis Series Copenhagen | 2021/10/18 07:00 | Yurii Dzhavakian v Felipe Mikkelsen | 6-0,6-1 |
| ITF M15 Doha | 2021/10/11 15:50 | Zura Tkemaladze v Felipe Mikkelsen | 6-1,6-1 |
| ITF M15 Doha Qual | 2021/10/10 13:30 | Tushar Madan v Felipe Mikkelsen | 6-7,3-6 |
| ITF M15 Doha | 2021/10/06 12:30 | Nico Hornitschek v Felipe Mikkelsen | 4-6,6-3,6-2 |
| ITF M15 Doha | 2021/10/04 12:00 | Essa Qabazard v Felipe Mikkelsen | 7-6,6-2 |
| ITF M15 Doha | 2021/10/03 12:00 | Theertha Shashank Macherla v Felipe Mikkelsen | 2-6,7-6,8-10 |
| ITF M25 Falun | 2021/09/26 11:00 | Karl Friberg v Felipe Mikkelsen | 6-1,6-1 |