Stadium: Court 1 Round: 26 Ground: Clay
| ITF Netherlands F2 | 2018/07/04 08:00 | Heliovaara, Harri v Kaczynski, Kevin | 6-3,6-1 |
| Challenger Blois | 2018/06/21 09:00 | Pedro Cachin v Heliovaara, Harri | 6-7,7-6,6-2 |
| Challenger Blois | 2018/06/19 16:00 | Frederico Ferreira Silva v Heliovaara, Harri | 6-3,5-7,6-7 |
| Challenger Blois Qual | 2018/06/18 10:15 | Heliovaara, Harri v Tristan Lamasine | 4-6,4-6 |
| Challenger Blois Qual | 2018/06/17 13:55 | Heliovaara, Harri v Arneodo, Romain | 4-6,7-6,7-6 |
| Challenger Blois Qual | 2018/06/16 15:45 | Heliovaara, Harri v Hach Verdugo, Hans | 6-1,6-4 |
| Challenger Lyon Qual | 2018/06/09 14:00 | Matteo Martineau v Heliovaara, Harri | 6-4,6-1 |
| Shymkent, Kazakhstan, Qualifying | 2018/06/02 07:00 | Heliovaara, Harri v Tung-Lin Wu | 6-7,3-6 |
| ITF Netherlands F2 | 2018/07/04 08:00 | Erdbories, Tillmann v Gerritsen, Stephan | 7-5,5-7,4-6 |
| ITF Netherlands F1 | 2018/06/30 13:25 | Geens, Clement v Gerritsen, Stephan | 7-5,6-4 |
| ITF Netherlands F1 | 2018/06/29 10:20 | Gerritsen, Stephan v Dhoe, Benjamin | 3-6,6-2,6-3 |
| ITF Netherlands F1 | 2018/06/28 11:40 | Gerritsen, Stephan v Ryan Nijboer | 6-4,7-6 |
| ITF Netherlands F1 | 2018/06/27 10:40 | Gabriel Decamps v Gerritsen, Stephan | 3-6,6-0,4-6 |
| ITF Belgium F1 | 2018/06/20 08:00 | Kenneth Raisma v Gerritsen, Stephan | 7-6,6-4 |
| Turkey F20, Singles Qualifying | 2018/05/23 09:50 | Cengiz Aksu v Gerritsen, Stephan | 6-4,6-2 |
| ITF Nigeria F3 | 2018/05/01 09:00 | Singh, Dalwinder v Gerritsen, Stephan | 6-2,7-6 |