Stadium: Court 1 Round: 25 Ground: Clay
| ITF M15 Prijedor | 2021/05/14 10:15 | Matheus Pucinelli De Almeida v Bozo Barun | 6-1,6-1 |
| ITF M15 Prijedor | 2021/05/11 08:00 | Matic Dimic v Bozo Barun | 2-6,6-2,7-10 |
| ITF M15 Prijedor | 2021/05/10 08:00 | Elgin Khoeblal v Bozo Barun | 2-6,5-7 |
| ITF M15 Prijedor | 2021/05/09 07:00 | Lilian Breut v Bozo Barun | 6-2,2-6,8-10 |
| ITF M15 Sibenik | 2021/04/21 12:40 | Alen Rogic-Hadzalic v Bozo Barun | 7-6,7-5 |
| Challenger Split | 2021/04/12 08:30 | Bozo Barun v Lukas Klein | 1-6,4-6 |
| Challenger Split Qual | 2021/04/11 11:30 | Gian Marco Moroni v Bozo Barun | 3-6,6-2,6-7 |
| Challenger Split | 2021/04/04 09:00 | Blaz Kavcic v Bozo Barun | 6-4,6-3 |
| ITF M15 Prijedor | 2021/05/11 14:35 | Naoki Tajima v Miljan Zekic | 6-7,4-6 |
| ITF M15 Majadahonda | 2021/05/03 12:00 | Naoki Tajima v Giovanni Mpetshi Perricard | 6-3,2-6,8-10 |
| ITF M15 Majadahonda | 2021/05/02 16:15 | Naoki Tajima v Hugo Pontico | 7-6,6-0 |
| ITF M15 LPD Gran Canaria | 2021/04/27 08:55 | Naoki Tajima v Alex M Pujolras | 1-6,2-6 |
| ITF M15 St Petersburg | 2021/04/17 08:00 | Naoki Tajima v Savriyan Danilov | 4-6,2-6 |
| ITF M15 St Petersburg | 2021/04/15 07:00 | Naoki Tajima v Marat Deviatiarov | 7-6,6-3 |
| ITF M15 St Petersburg | 2021/04/14 11:55 | Naoki Tajima v Alexander Wolfschmidt | 6-1,6-2 |
| ITF M15 St Petersburg | 2021/04/07 07:00 | Naoki Tajima v Alexey Zakharov | 3-6,6-1,3-6 |