| UTR Pro Tennis Series Copenhagen | 2021/10/21 07:00 | Nikolaj Katic v Felipe Mikkelsen | 6-4,6-2 |
| 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 |
| UTR Pro Tennis Series Copenhagen | 2021/10/22 10:00 | Jose Antonio Rodriguez Rodriguez v Albert P Hansen | 6-4,6-2 |
| UTR Pro Tennis Series Copenhagen | 2021/10/21 10:00 | Jose Antonio Rodriguez Rodriguez v Arslan Temirhanov | 4-6,1-6 |
| UTR Pro Tennis Series Copenhagen | 2021/10/20 08:30 | Deni Zmak v Jose Antonio Rodriguez Rodriguez | 6-1,5-2 |
| UTR Pro Tennis Series Copenhagen | 2021/10/19 08:30 | Maxim Landa v Jose Antonio Rodriguez Rodriguez | 4-6,7-6,6-6 |
| UTR Pro Tennis Series Mulheim | 2021/10/17 08:30 | Quin Verstegen v Jose Antonio Rodriguez Rodriguez | 6-3,6-4 |
| UTR Pro Tennis Series Mulheim | 2021/10/16 14:00 | Edison Ambarzumjan v Jose Antonio Rodriguez Rodriguez | 2-6,2-6 |
| UTR Pro Tennis Series Mulheim | 2021/10/15 10:00 | Jose Antonio Rodriguez Rodriguez v Finn Bischof | 4-6,7-6,2-6 |
| UTR Pro Tennis Series Mulheim | 2021/10/14 10:00 | Jose Antonio Rodriguez Rodriguez v Benjamin Hassan | 4-6,1-6 |