| ITF M15 Heraklion | 11/19 07:30 | 62 | Filippo Francesco Garbero v Jonas P Hartenstein | 6-1,6-3 | |
| ITF M15 Heraklion | 11/18 09:30 | 62 | Nazar Oliynykov v Jonas P Hartenstein | 7-5,2-6,7-10 | |
| ITF M15 Heraklion | 11/14 09:00 | 26 | Jonas P Hartenstein v Adria Soriano Barrera | 4-6,1-6 | |
| ITF M15 Heraklion | 11/13 09:30 | 25 | Jonas P Hartenstein v Dylan Waldorf Martin | Retired | |
| ITF M25 Heraklion | 11/12 08:00 | 62 | Jonas P Hartenstein v Gabriel Matuszewski | 6-4,6-3 | |
| ITF M25 Heraklion | 11/11 08:00 | 62 | Mats Bredschneijder v Jonas P Hartenstein | 6-7,3-6 | |
| ITF M25 Heraklion | 11/07 13:10 | 26 | Jonas P Hartenstein v Gabriel Debru | 4-6,3-6 | |
| ITF M25 Heraklion | 11/06 12:05 | 25 | Jonas P Hartenstein v Stylianos Christodoulou | 3-6,6-3,6-4 | |
| ITF M25 Heraklion | 11/05 08:00 | 62 | Sergis Kyratzis v Jonas P Hartenstein | 5-7,0-6 | |
| ITF M25 Heraklion | 11/04 08:00 | 62 | Ainius Sabaliauskas v Jonas P Hartenstein | 6-7,5-7 | |
| ITF M25 Heraklion | 11/03 10:00 | 62 | Jonas P Hartenstein v Edison Ambarzumjan | 6-4,6-4 | |
| ITF M15 Kayseri | 10/14 07:00 | 62 | Jonas P Hartenstein v Alp Horoz | 2-6,3-6 | |
| ITF M15 Kayseri | 10/13 07:00 | 62 | Jonas P Hartenstein v Aarwin Saravanan | 6-1,6-1 | |
| ITF M15 Trnava | 09/23 08:00 | 54 | Boris Butulija v Jonas P Hartenstein | 6-2,6-3 | |
| ITF M15 Trier | 08/21 12:35 | 25 | Mats Rosenkranz v Jonas P Hartenstein | 6-2,7-6 | |
| ITF M15 Trier | 08/19 12:30 | 54 | Jonas P Hartenstein v Karlo Cubelic | 3-6,6-3,10-8 | |
| ITF M15 Trier | 08/19 09:00 | 54 | Jonas P Hartenstein v Martijn Molenkamp | 6-1,6-2 | |
| ITF M25 Kassel | 07/08 13:00 | 54 | Jonas P Hartenstein v Christian Hansen | 6-1,2-6,10-12 | |
| ITF M15 Kamen | 06/26 17:25 | 25 | Jonas P Hartenstein v Svyatoslav Gulin | 2-6,4-6 | |
| ITF M15 Kamen | 06/24 12:00 | 54 | Taym Alazmeh v Jonas P Hartenstein | 3-6,5-7 | |
| ITF M15 Kamen | 06/24 08:30 | 54 | Michalis Sakellaridis v Jonas P Hartenstein | 2-6,3-6 | |
| ITF M15 Koszalin | 06/12 07:00 | 44 | Maciej Rajski v Jonas P Hartenstein | 6-4,6-2 | |
| ITF M15 Koszalin | 06/10 14:00 | 44 | Kacper Szymkowiak v Jonas P Hartenstein | 7-5,5-7,9-11 | |
| ITF M15 Orange Park | 05/02 15:00 | 26 | Rudy Quan v Jonas P Hartenstein | Walkover | |
| ITF M15 Orange Park | 04/30 18:40 | 25 | Juan I Cabrera v Jonas P Hartenstein | 3-6,1-6 | |
| ITF M25 Trnava | 11/07 11:10 | 54 | Matvey Minin v Jonas P Hartenstein | 6-3,6-7,10-6 | |
| ITF M25 Trnava | 11/06 11:00 | 54 | Patrik Homola v Jonas P Hartenstein | 2-6,2-6 | |
| ITF M25 Pardubice | 09/20 12:45 | 25 | Jonas P Hartenstein v Maxime Chazal | 3-6,4-6 | |
| ITF M25 Pardubice | 09/19 08:00 | 62 | Jonas P Hartenstein v Roman Postolka | 4-6,4-6 | |
| ITF M25 Pardubice | 09/18 08:00 | 62 | Jonas P Hartenstein v Matej Rudolf | 6-1,6-0 |