Stadium: Center Court Round: 24 Ground: Clay
| ITF Germany F15 | 2015/10/07 09:25 | Louis Wessels v Johannes Haerteis | 0-6,4-6 |
| Challenger Sopot | 2019/07/29 15:15 | Martin Cuevas v Johannes Haerteis | 7-6,6-4 |
| ATP Hamburg | 2019/07/20 09:30 | Alejandro Davidovich Fokina v Johannes Haerteis | 6-2,6-3 |
| Challenger Braunschweig | 2019/07/10 11:20 | Johannes Haerteis v Tobias Kamke | 5-7,1-6 |
| Challenger Braunschweig | 2019/07/09 10:50 | Rudolf Molleker v Johannes Haerteis | 6-3,5-7,1-6 |
| Challenger Braunschweig | 2019/07/07 14:35 | Cedrik-Marcel Stebe v Johannes Haerteis | 6-3,5-7,4-6 |
| Challenger Ludwigshafen | 2019/07/03 09:00 | Johannes Haerteis v Yannick Hanfmann | 3-6,3-6 |
| Challenger Ludwigshafen | 2019/07/02 09:00 | Johannes Haerteis v Julian Lenz | 3-6,7-6,7-6 |
| Challenger Prostejov | 2019/06/03 12:20 | Arthur De Greef v Johannes Haerteis | 4-6,4-6 |
| Challenger Liberec | 2019/07/31 12:35 | Daniel Gimeno-Traver v Louis Wessels | 6-4,3-6,6-3 |
| Challenger Liberec | 2019/07/29 13:00 | Corentin Denolly v Louis Wessels | 4-6,6-1,3-6 |
| ITF M25 Kassel | 2019/07/20 12:10 | Lucas Gerch v Louis Wessels | 7-5,6-4 |
| ITF M25 Kassel | 2019/07/19 12:35 | Louis Wessels v Chun Hsin Tseng | 6-7,7-6,6-4 |
| ITF M25 Kassel | 2019/07/18 11:05 | Louis Wessels v Federico Moreno | 7-6,6-4 |
| ITF M25 Kassel | 2019/07/17 14:10 | Louis Wessels v Adrien Bossel | 7-6,6-4 |
| ITF M15 Marburg | 2019/07/14 12:00 | Louis Wessels v Jesper De Jong | 7-6,7-6 |
| ITF M15 Marburg | 2019/07/12 09:40 | Louis Wessels v Kai Wehnelt | 6-2,7-6 |