| 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 |
| UTR Pro Tennis Series Copenhagen | 2021/06/17 09:30 | Dominik Palan v Warren Sinius | 2-2 |
| UTR Pro Tennis Series Copenhagen | 2021/06/16 11:00 | Philip Hjorth v Warren Sinius | 6-3,6-5 |
| UTR Pro Tennis Series Copenhagen | 2021/06/14 09:30 | Marius Ruzgas v Warren Sinius | 6-2,6-0 |
| UTR Pro Tennis Series Bucharest | 2021/06/04 11:30 | Warren Sinius v Valentin Vanta | 0-6,2-6 |
| UTR Pro Tennis Series Bucharest | 2021/06/03 07:30 | Marcelo Zormann v Warren Sinius | 6-0,6-0 |
| UTR Pro Tennis Series Bucharest | 2021/06/02 12:00 | Ihor Dudun v Warren Sinius | 4-6,0-6 |