Stadium: Court 1 Round: 25 Ground: Clay
| Challenger Glasgow Qual | 2018/04/29 15:00 | Heliovaara, Harri v Bossel, Adrien | 2-6,7-6,6-4 |
| ITF Estonia F4 | 2017/11/08 13:00 | Bossel, Adrien v Heliovaara, Harri | 6-7,6-7 |
| Jinan, China | 2018/08/09 10:40 | Heliovaara, Harri v Denis Yevseyev | 2-6,4-6 |
| Jinan, China | 2018/08/07 07:30 | Ramkumar Ramanathan v Heliovaara, Harri | 3-6,4-6 |
| Chengdu, China | 2018/07/31 04:35 | Akira Santillan v Heliovaara, Harri | 6-7,7-5,7-6 |
| Challenger Tampere | 2018/07/24 16:00 | Heliovaara, Harri v Antoine Hoang | 0-6,4-6 |
| ITF Netherlands F2 | 2018/07/07 16:05 | Heliovaara, Harri v Jelle Sels | 6-4,4-6,4-6 |
| ITF Netherlands F2 | 2018/07/06 12:15 | Heliovaara, Harri v Denis Klok | 3-1 |
| ITF Netherlands F2 | 2018/07/05 08:00 | Heliovaara, Harri v Gerritsen, Stephan | 6-2,7-5 |
| ITF Netherlands F2 | 2018/07/04 08:00 | Heliovaara, Harri v Kaczynski, Kevin | 6-3,6-1 |
| ITF Switzerland F4 | 2018/08/28 15:15 | Bossel, Adrien v Florent Bax | 1-6,6-7 |
| ITF Switzerland F3 | 2018/08/23 15:30 | Jacopo Berrettini v Bossel, Adrien | 7-5,5-7,6-3 |
| ITF Switzerland F3 | 2018/08/22 11:30 | Bossel, Adrien v Gomez, Lucas | 7-6,6-7,6-3 |
| Challenger Lisbon Qual | 2018/05/12 13:00 | Bossel, Adrien v Alejandro Davidovich Fokina | 1-6,1-6 |
| Challenger Glasgow Qual | 2018/04/29 15:00 | Heliovaara, Harri v Bossel, Adrien | 2-6,7-6,6-4 |
| Challenger Glasgow Qual | 2018/04/28 13:00 | Thomson, Connor v Bossel, Adrien | 3-6,4-6 |
| ITF Spain F10 | 2018/04/26 09:00 | Bossel, Adrien v Reboul, Fabien | 1-6,3-6 |
| ITF Spain F10 Qual | 2018/04/23 11:20 | Bossel, Adrien v Benjamin Winter Lopez | 6-4,6-2 |