| 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 |
| 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 - Bukarest | 2021/06/04 11:30 | Warren Sinius v Valentin Vanta | 0-6,2-6 |
| UTR Pro Tennis Series Zadar | 2021/06/28 12:30 | Frane Nincevic v Jerko Brkic | 6-1,7-5 |
| ITF M15 Sarajevo | 2021/06/02 09:00 | Frane Nincevic v Mathieu Perchicot | 6-2,2-6,4-6 |
| ITF M15 Sibenik | 2021/05/17 08:00 | Nikola Basic v Frane Nincevic | 6-7,6-1,10-8 |
| Challenger Zagreb | 2021/05/09 08:30 | Frane Nincevic v Ramkumar Ramanathan | 4-6,3-6 |
| ITF M15 Sibenik | 2021/04/21 08:00 | Sebastian Prechtel v Frane Nincevic | 6-0,6-3 |
| Challenger Split - Kval | 2021/04/11 12:25 | Frane Nincevic v Tristan Lamasine | 1-6,5-7 |
| Challenger Zadar | 2021/03/24 09:00 | Frane Nincevic v Sumit Nagal | 0-6,1-6 |
| Challenger Zadar | 2021/03/22 13:15 | Frane Nincevic v Mili Poljicak | 4-6,6-4,6-3 |