Stadium: Court 9 Round: 44 Ground: Hardcourt outdoor
| ITF M15 Doha | 2021/10/07 14:50 | Christian Sigsgaard v Boris Butulija | 6-1,6-3 |
| ITF M15 Doha | 2021/10/06 14:20 | Boris Butulija v Mousa Alkotop | 7-5,3-6,6-1 |
| ITF M15 Sozopol | 2021/09/15 07:00 | Aleksandre Bakshi v Boris Butulija | 6-1,2-6,7-5 |
| ITF M15 Cairo | 2021/09/01 14:25 | Maxime Mora v Boris Butulija | 6-0,2-6,6-4 |
| ITF M15 Bratislava | 2021/08/17 08:00 | Boris Butulija v Tomas Liska | 3-6,1-6 |
| ITF M15 Bratislava | 2021/08/16 10:30 | Boris Butulija v Martin Machala | 6-0,6-3 |
| ITF M15 Telavi | 2021/08/02 12:00 | Boris Butulija v Marco De Rossi | 4-6,5-7 |
| ITF M15 Telavi | 2021/08/02 06:00 | Boris Butulija v Danial Rakhmatullayev | 6-0,6-4 |
| 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 |
| ITF M25 Jonkoping | 2021/09/19 11:00 | Ben Jones v Nikolaj Katic | 6-2,6-7,10-6 |
| UTR Pro Tennis Series Ricany | 2021/09/08 09:00 | Nikolaj Katic v Jiri Barnat | 1-6,0-2 |
| UTR Pro Tennis Series Ricany | 2021/09/07 13:00 | Nikolaj Katic v Maxence Broville | 3-6,3-6 |
| ITF M25 Muttenz | 2021/08/16 07:55 | Mischa Lanz v Nikolaj Katic | 7-5,6-4 |