| Challenger Szczecin | 09/11 14:00 | 25 | [49] Albert Ramos-Vinolas v Johannes Haerteis [381] | 6-2,6-4 | |
| Challenger Szczecin | 09/09 12:00 | 24 | [381] Johannes Haerteis v Mathieu Perchicot [437] | 2-6,6-4,6-2 | |
| Challenger L'Aquila | 08/24 14:55 | 27 | [262] Dmitry Popko v Johannes Haerteis [412] | 7-6,6-2 | |
| Challenger L'Aquila | 08/22 09:35 | 26 | [363] Juan P Ficovich v Johannes Haerteis [412] | 3-6,6-7 | |
| Challenger L'Aquila | 08/21 08:00 | 25 | [412] Johannes Haerteis v Nino Serdarusic [267] | 7-6,6-3 | |
| Challenger L'Aquila | 08/19 09:40 | 24 | [336] Riccardo Bonadio v Johannes Haerteis [412] | 4-6,4-6 | |
| Challenger Meerbusch | 08/14 12:45 | 25 | [419] Johannes Haerteis v Benjamin Hassan [293] | Retired | |
| Challenger Meerbusch | 08/13 09:40 | 24 | [419] Johannes Haerteis v Eduard Esteve Lobato [374] | 6-4,7-5 | |
| Challenger Augsburg | 08/06 08:00 | 24 | [417] Johannes Haerteis v Louis Wessels [356] | 6-7,5-7 | |
| Challenger Sopot | 07/29 15:15 | 24 | [328] Martin Cuevas v Johannes Haerteis [345] | 7-6,6-4 | |
| ATP Hamburg | 07/20 09:30 | 64 | Alejandro D-Fokina v Johannes Haerteis | 6-2,6-3 | |
| Challenger Braunschweig | 07/10 11:20 | 26 | [363] Johannes Haerteis v Tobias Kamke [266] | 5-7,1-6 | |
| Challenger Braunschweig | 07/09 10:50 | 25 | [147] Rudolf Molleker v Johannes Haerteis [363] | 6-3,5-7,1-6 | |
| Challenger Braunschweig | 07/07 14:35 | 24 | Cedrik-Marcel Stebe v Johannes Haerteis | 6-3,5-7,4-6 | |
| Challenger Ludwigshafen | 07/03 09:00 | 25 | [363] Johannes Haerteis v Yannick Hanfmann [212] | 3-6,3-6 | |
| Challenger Ludwigshafen | 07/02 09:00 | 24 | [363] Johannes Haerteis v Julian Lenz [342] | 3-6,7-6,7-6 | |
| Challenger Parma | 06/17 08:00 | 24 | [359] Johannes Haerteis v Sandro Ehrat [396] | Retired | |
| Challenger Prostejov | 06/05 09:00 | 26 | Johannes Haerteis v Attila Balazs | Walkover | |
| Challenger Prostejov | 06/03 12:20 | 25 | [181] Arthur De Greef v Johannes Haerteis [364] | 4-6,4-6 | |
| Challenger Prostejov | 06/02 14:40 | 24 | [274] Benjamin Lock v Johannes Haerteis [364] | 6-2,2-6,3-6 | |
| Challenger Jerusalem | 05/20 07:00 | 24 | [363] Johannes Haerteis v Gonzalo Escobar [323] | 3-6,7-5,2-6 | |
| Challenger Rome | 05/07 12:10 | 25 | [372] Johannes Haerteis v Stefano Napolitano [189] | 2-6,3-6 | |
| Challenger Rome | 05/06 10:00 | 24 | [465] Skander Mansouri v Johannes Haerteis [371] | 6-7,7-6,5-7 | |
| Challenger Savannah | 04/30 14:00 | 24 | Cannon Kingsley v Johannes Haerteis | 6-2,6-2 | |
| Challenger Tallahassee | 04/24 14:00 | 25 | [175] Mitchell Krueger v Johannes Haerteis [375] | 3-6,6-4,6-1 | |
| Challenger Tallahassee | 04/23 16:40 | 24 | [375] Johannes Haerteis v Evan Song [331] | 6-4,6-4 | |
| Challenger Tallahassee | 04/22 14:00 | 166 | [371] Benjamin Hassan v Johannes Haerteis [375] | 6-4,6-1 | |
| Challenger Sarasota | 04/15 14:00 | 166 | [374] Harri Heliovaara v Johannes Haerteis [373] | 6-3,6-2 | |
| Challenger Sarasota | 04/15 14:00 | 166 | Aleksandar Vukic v Johannes Haerteis | Cancelled | |
| Challenger Barletta | 04/09 13:55 | 24 | [374] Johannes Haerteis v Andrea Pellegrino [359] | 4-6,4-6 |