Stadium: Court 1 Round: 44 Ground: Clay
| ITF M15 Sibenik | 2021/04/19 12:15 | Ondrej Horak v Boris Butulija | 6-2,7-6 |
| Challenger Belgrade | 2021/04/11 10:00 | Dmitry Popko v Boris Butulija | 6-2,6-1 |
| ITF M15 Antalya | 2021/03/21 07:00 | Boris Butulija v Bautista Vilicich | 6-4,5-7,9-11 |
| ITF M15 Antalya | 2021/03/14 07:00 | Vladimir Korolev v Boris Butulija | 6-0,6-0 |
| ITF M15 Kazan | 2021/03/09 10:45 | Aleksei Khomich v Boris Butulija | 7-6,6-3 |
| ITF M15 Kazan | 2021/03/08 08:00 | Rail Ibragimov v Boris Butulija | 6-4,4-6,7-10 |
| Eastern European Championship | 2020/11/26 15:20 | Dan Alexandru Tomescu v Boris Butulija | 5-7,2-6 |
| Eastern European Championship | 2020/11/25 16:00 | Duje Kekez v Boris Butulija | 7-6,7-6 |
| ITF M15 Brcko | 2021/05/16 14:00 | Drazen Petrovic v Milan Macura | 6-2,6-1 |
| ITF M15 Prijedor | 2021/05/09 09:30 | Drazen Petrovic v Lazar Vojinovic | 3-6,6-0,4-10 |
| ITF M15 Antalya | 2021/01/04 07:00 | Jorge Martinez Martinez v Drazen Petrovic | 6-0,6-1 |
| ITF M15 Antalya | 2021/01/03 07:00 | Sven Corbinais v Drazen Petrovic | 4-6,2-6 |