Stadium: Center Court Round: 25 Ground: Hardcourt outdoor
| Challenger Lisbon Qual | 2018/05/12 13:35 | Christopher Heyman v David Vega Hernandez | 1-6,3-6 |
| Challenger Braga | 2018/05/08 17:25 | Pedro Sousa v Christopher Heyman | 6-2,6-2 |
| Challenger Guadalajara | 2018/04/17 17:00 | Christopher Heyman v Alexander Sarkissian | 4-6,6-7 |
| Challenger Mexico City | 2018/04/09 22:25 | Christopher Heyman v Adrian Menendez-Maceiras | 6-1,5-7,2-6 |
| ITF Portugal F6 | 2018/03/29 11:00 | Andres Artunedo Martinavarr v Christopher Heyman | 6-2,6-1 |
| ITF Portugal F6 | 2018/03/28 14:45 | Jaime Pulgar-Garcia v Christopher Heyman | 3-6,2-6 |
| ITF Portugal F6 | 2018/03/27 15:20 | Kenneth Raisma v Christopher Heyman | 4-6,7-6,6-7 |
| ITF Switzerland F2 | 2018/02/14 14:00 | Christopher Heyman v Niels Desein | 6-7,4-6 |
| ITF Poland F3 | 2018/05/14 10:30 | Jonathan Gray v Pawel Juszczak | 4-6,4-6 |
| ITF Poland F2 | 2018/05/11 09:30 | Jonathan Gray v Maxim Ratniuk | 0-6,1-6 |
| ITF Poland F2 | 2018/05/10 12:30 | Jonathan Gray v Daniel Kossek | 6-3,6-1 |
| ITF Poland F2 | 2018/05/08 08:00 | Jonathan Gray v Maciej Smola | 6-1,6-4 |
| Challenger Glasgow | 2018/05/01 10:45 | Harri Heliovaara v Jonathan Gray | 6-3,6-1 |
| ITF France F8 | 2018/04/25 09:00 | Jonathan Gray v Gregoire Jacq | 0-6,2-6 |
| ITF France F8 | 2018/04/23 16:30 | Robin Kern v Jonathan Gray | 3-6,2-6 |
| ITF Greece F5 | 2018/03/30 07:30 | Jonathan Gray v Yaraslav Shyla | 4-6,2-6 |