| UTR Pro Tennis Series - Copenhaga | 2021/06/20 09:30 | Daniel De Jonge v Sebastian Grundtvig Jorgensen | 6-4,4-6,2-6 |
| UTR Pro Tennis Series - Copenhaga | 2021/06/18 08:00 | Sebastian Grundtvig Jorgensen v Gustav Theilgaard | 6-4,6-2 |
| UTR Pro Tennis Series - Copenhaga | 2021/06/16 09:30 | Sebastian Grundtvig Jorgensen v Henrik Heise Korsgaard | 6-3,6-5 |
| UTR Pro Tennis Series - Copenhaga | 2021/06/15 12:30 | Sebastian Grundtvig Jorgensen v Leo Borg | 6-3,5-2 |
| UTR Pro Tennis Series - Copenhaga | 2021/06/14 10:15 | Maxim Landa v Sebastian Grundtvig Jorgensen | 2-6,5-7 |
| UTR Pro Tennis Series - Copenhaga | 2021/06/14 08:00 | Robert Rumler v Sebastian Grundtvig Jorgensen | 0-0 |
| ITF - M15 Ystad | 2019/08/06 08:15 | David Volfson v Sebastian Grundtvig Jorgensen | 6-2,6-2 |
| ITF - M15 Ystad | 2019/08/05 09:25 | Sebastian Grundtvig Jorgensen v Jan Jermar | 6-1,6-0 |
| ITF - M15 Antália | 2022/01/13 11:00 | Juan P Canas Garcia v Nikolaj Katic | 6-4,6-0 |
| ITF - M15 Parnu | 2021/10/26 08:00 | Raffael Schaer v Nikolaj Katic | 7-5,6-4 |
| UTR Pro Tennis Series - Copenhaga | 2021/10/23 07:00 | Nikolaj Katic v Jose Antonio Rodriguez Rodriguez | 6-7,2-6 |
| UTR Pro Tennis Series - Copenhaga | 2021/10/21 07:00 | Nikolaj Katic v Felipe Mikkelsen | 6-4,6-2 |
| UTR Pro Tennis Series - Copenhaga | 2021/10/20 13:15 | Nikolaj Katic v Vilhelm Fridell | 5-7,6-4,1-6 |
| UTR Pro Tennis Series - Copenhaga | 2021/10/19 11:30 | Nikolaj Katic v Yurii Dzhavakian | 4-6,4-6 |
| UTR Pro Tennis Series - Copenhaga | 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 |