| UTR Pro Tennis Series Bucharest | 2021/05/30 10:00 | Ihor Dudun v Marcelo Zormann | 1-6,0-6 |
| UTR Pro Tennis Series Bucharest | 2021/05/30 13:00 | Mihai Razvan Marinescu v Warren Sinius | 6-4,6-1 |
| ITF M15 Marbella | 2021/05/23 12:30 | Jose Dominguez Alonso v Warren Sinius | 6-2,2-6,10-6 |
| UTR Pro Tennis Series Barcelona | 2021/05/01 11:00 | Warren Sinius v Fermin Calvo Barcelo | 0-6,0-5 |
| UTR Pro Tennis Series Barcelona | 2021/04/30 12:30 | Kuzey Cekirge v Warren Sinius | 5-7,6-0,6-4 |
| UTR Pro Tennis Series Barcelona | 2021/04/29 10:00 | Thomas Laurent v Warren Sinius | 6-1,5-1 |
| ITF M15 Poitiers | 2021/03/15 11:10 | Warren Sinius v Hugo Voljacques | 0-6,0-6 |
| ITF M15 Poitiers | 2021/03/14 12:30 | Warren Sinius v Nicolas Tepmahc | 6-1,6-7,10-5 |
| ITF M25 Plaisir | 2019/09/16 15:30 | Jonathan Eysseric v Warren Sinius | 6-1,6-2 |