Round: 25 Ground: Clay
| ITF USA F12 | 2018/04/25 16:00 | Jordi Arconada v Collin Johns | 6-2,6-4 |
| ITF USA F11 | 2018/04/17 14:00 | Ricardo Rodriguez-Pace v Collin Johns | 6-3,6-2 |
| ITF Israel F3 | 2018/03/21 08:00 | Collin Johns v Mor Bulis | 2-6,3-6 |
| ITF Israel F1 | 2018/03/06 08:00 | Collin Johns v Yannick Vandenbulcke | 0-6,3-6 |
| ITF Israel F1 | 2018/03/04 10:30 | Collin Johns v Motvey Radionov | 6-3,6-4 |
| ITF Israel F1 | 2018/03/04 08:00 | Collin Johns v Amit Cohen | 6-0,6-0 |
| ITF USA F6 | 2018/01/31 15:00 | Fred Gil v Collin Johns | 6-0,6-2 |
| ITF USA F6 | 2018/01/29 16:00 | Collin Johns v Alex Hernandez | 6-1,6-7,6-7 |
| ITF Bulgaria F1 | 2018/05/17 07:00 | Markos Kalovelonis v Vasil Kirkov | 7-6,4-6,3-6 |
| ITF Bulgaria F1 | 2018/05/16 08:20 | Markos Kalovelonis v Daniil Zarichanskiy | 6-1,6-3 |
| ITF Uzbekistan F2 | 2018/04/25 09:00 | Markos Kalovelonis v Dzmitry Zhyrmont | 5-7,3-6 |
| ITF Uzbekistan F2 | 2018/04/24 14:45 | Shonigmatjon Shofayziyev v Markos Kalovelonis | 1-6,5-7 |
| ITF Kazakhstan F4 | 2018/04/18 06:30 | Markos Kalovelonis v Teymuraz Gabashvili | 4-6,3-6 |
| ITF Kazakhstan F4 | 2018/04/17 05:50 | Markos Kalovelonis v Matvey Khomentovskiy | 7-6,7-6 |
| Davis Cup | 2018/04/06 10:15 | Ljubomir Celebic v Markos Kalovelonis | 6-2,6-1 |
| Davis Cup | 2018/04/04 09:10 | Martins Podzus v Markos Kalovelonis | 3-6,4-6 |