Stadium: Court 3 Round: 54 Ground: Carpet indoor
| UTR Pro Tennis Series Zadar | 2021/07/04 07:00 | Bozo Barun v Warren Sinius | 6-1,6-0 |
| UTR Pro Tennis Series Zadar | 2021/07/01 09:30 | Warren Sinius v Jerko Brkic | 6-3,6-5 |
| UTR Pro Tennis Series Zadar | 2021/06/30 08:00 | Warren Sinius v Constant De La Bassetiere | 3-6,6-6 |
| UTR Pro Tennis Series Zadar | 2021/06/29 11:00 | Warren Sinius v Frane Nincevic | 5-7,3-6 |
| UTR Pro Tennis Series Zadar | 2021/06/28 12:30 | Warren Sinius v Josip Krstanovic | 2-6,1-5 |
| UTR Pro Tennis Series Copenhagen | 2021/06/20 08:00 | Alexander Konigsfeldt v Warren Sinius | 6-1,6-0 |
| UTR Pro Tennis Series Copenhagen | 2021/06/19 07:00 | Nikolaj Katic v Warren Sinius | 4-5 |
| UTR Pro Tennis Series Copenhagen | 2021/06/18 12:30 | Ludvig Aaes v Warren Sinius | 7-6,6-2 |
| ITF M25 Wroclaw | 2021/06/27 14:00 | Dominik Langmajer v Mateusz Terczynski | 1-6,3-6 |
| ITF M15 Gaiba | 2021/06/07 09:45 | Francesco Vilardo v Dominik Langmajer | 7-5,6-3 |
| ITF M15 Jerusalem | 2021/05/09 08:30 | Alexandros Skorilas v Dominik Langmajer | 6-2,6-0 |
| ITF M15 Sharm El Sheikh | 2021/03/21 13:00 | Dominik Langmajer v Kousuke Ogura | 3-6,2-6 |
| ITF M15 Sharm El Sheikh | 2021/03/14 07:00 | Dominik Langmajer v Emiliano Troche | 2-6,4-6 |
| ITF M15 Sharm El Sheikh | 2021/03/07 07:00 | Dominik Langmajer v Alexandros Skorilas | 3-6,1-6 |
| ITF M15 Sharm El Sheikh | 2020/11/01 09:30 | Dominik Langmajer v Simon Beaupain | 3-6,2-6 |
| ITF M15 Sharm El Sheikh | 2020/10/28 12:40 | Dominik Langmajer v Alexey Zakharov | 3-6,2-6 |