Stadium: Court 8 Round: 46 Ground: Clay
| ITF Switzerland F1 | 2018/02/06 12:00 | Johannes Haerteis v Julian Lenz | 6-2,1-6,4-6 |
| ITF Czech Republic F2 | 2017/05/27 11:55 | Julian Lenz v Johannes Haerteis | 6-1,6-4 |
| ITF Germany F10 | 2016/08/11 14:25 | Julian Lenz v Johannes Haerteis | 5-7,6-3,3-6 |
| Challenger Sibiu | 2018/09/15 07:30 | Vit Kopriva v Johannes Haerteis | 4-6,1-6 |
| ITF Romania F13 | 2018/09/13 06:30 | Johannes Haerteis v Gabriel Alejandro Hidalgo | 4-6,5-7 |
| ITF Romania F13 | 2018/09/11 06:30 | Johannes Haerteis v Gabi Adrian Boitan | 6-3,6-2 |
| ITF Germany F13 | 2018/08/23 08:00 | Peter Heller v Johannes Haerteis | 6-1,6-0 |
| ITF Germany F13 | 2018/08/21 15:00 | Florian Fallert v Johannes Haerteis | 2-6,3-6 |
| Challenger Pullach Qual | 2018/08/04 15:55 | Alexandre Muller v Johannes Haerteis | 7-6,7-5 |
| Challenger Sopot Qual | 2018/07/29 09:00 | Roberto Marcora v Johannes Haerteis | 6-4,7-5 |
| Challenger Sopot Qual | 2018/07/28 10:40 | Johannes Haerteis v Kamil Gajewski | 6-3,6-2 |
| Challenger Sibiu | 2018/09/15 09:40 | George Iulian Dina v Julian Lenz | 1-6,2-6 |
| Challenger Szczecin | 2018/09/10 09:00 | Julian Lenz v Jan Satral | 2-6,3-6 |
| Challenger Szczecin | 2018/09/09 11:10 | Gonzalo Lama v Julian Lenz | 4-6,6-7 |
| Challenger Szczecin Qual | 2018/09/08 15:00 | Fernando Romboli v Julian Lenz | 1-6,1-6 |
| ITF Germany F13 | 2018/08/23 13:15 | Julian Lenz v Christoph Negritu | 6-7,0-6 |
| ITF Germany F13 | 2018/08/22 08:00 | Julian Lenz v Gabriel Schmidt | 6-3,6-3 |
| ITF Germany F13 | 2018/08/20 09:00 | Julian Lenz v Marvin Rehberg | 6-4,6-3 |
| ITF Germany F13 | 2018/08/19 14:00 | Julian Lenz v Laurin Aerne | 6-1,6-1 |