Stadium: Court 4 Round: 25 Ground: Clay
| ITF M15 Sibenik | 2021/04/20 08:00 | Domagoj Biljesko v Christian Sigsgaard | 6-1,6-7,4-10 |
| ITF M15 Sibenik | 2021/04/19 09:15 | Domagoj Biljesko v Luka Mikrut | 6-4,7-5 |
| ITF M15 Sibenik | 2021/04/18 10:00 | Domagoj Biljesko v Peter Samosi | 6-2,6-2 |
| ITF M15 Opatija | 2021/03/23 09:00 | Matic Spec v Domagoj Biljesko | 7-5,6-2 |
| ITF M15 Opatija | 2021/03/22 11:45 | Tadija Radovanovic v Domagoj Biljesko | 6-7,1-6 |
| ITF M15 Rovinj | 2021/03/15 08:30 | Domagoj Biljesko v Victor Vlad Cornea | 3-6,7-5,5-10 |
| ITF M15 Porec | 2021/03/08 14:00 | Mauro De Maio v Domagoj Biljesko | 6-3,7-6 |
| ITF M15 Porec | 2021/03/07 14:30 | Luka Petrovic v Domagoj Biljesko | 5-7,6-3,8-10 |
| ITF M15 Prijedor | 2021/05/12 10:30 | Joao Lucas Reis da Silva v Tim Heger | 6-3,7-5 |
| ITF M15 Prijedor | 2021/05/11 09:30 | Alen Rogic-Hadzalic v Tim Heger | 6-3,4-6,7-10 |
| ITF M15 Prijedor | 2021/05/10 13:30 | Nicolas Zanellato v Tim Heger | 6-4,3-6,7-10 |
| ITF M15 Prijedor | 2021/05/09 12:30 | Tadija Radovanovic v Tim Heger | 3-6,3-6 |
| ITF M15 Sibenik | 2021/04/21 08:00 | Tim Heger v Marco Miceli | 3-6,4-6 |
| ITF M15 Sibenik | 2021/04/20 10:05 | George Botezan v Tim Heger | 6-3,4-6,9-11 |
| ITF M15 Sibenik | 2021/04/19 14:30 | Borna Devald v Tim Heger | 3-6,2-6 |
| ITF M15 Opatija | 2021/03/21 11:00 | Ivan Karlo Ban v Tim Heger | 6-3,2-6,10-8 |