| 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 | |
| ITF M15 Koszalin | 09/06 09:25 | 25 | Jonas P Hartenstein v Maciej Rajski | 4-6,4-6 | |
| ITF M15 Szczawno | 09/01 09:00 | 27 | Olaf Pieczkowski v Jonas P Hartenstein | 6-2,6-2 | |
| ITF M15 Szczawno | 08/31 12:00 | 26 | Jonas P Hartenstein v Valerio Perruzza | Retired | |
| ITF M15 Szczawno | 08/29 12:45 | 25 | Michal Mikula v Jonas P Hartenstein | 1-6,0-6 | |
| ITF M25 Marburgo | 07/05 09:00 | 25 | Alex Rybakov v Jonas P Hartenstein | 6-4,6-0 | |
| ITF M25 Marburgo | 07/04 08:00 | 54 | Jonas P Hartenstein v Martin Benes | 3-6,6-3,10-7 | |
| ITF M25 Risskov/Aarhus | 06/15 11:55 | 26 | Max Houkes v Jonas P Hartenstein | 6-7,6-4,6-3 | |
| ITF M25 Risskov/Aarhus | 06/14 10:40 | 25 | Olle Wallin v Jonas P Hartenstein | 2-6,4-6 | |
| ITF M25 Jablonec Nad Nisou | 05/30 10:15 | 62 | Peter Goldsteiner v Jonas P Hartenstein | 7-5,7-5 | |
| ITF M25 Jablonec Nad Nisou | 05/29 09:00 | 62 | Patrik Oplustil v Jonas P Hartenstein | 3-6,0-6 | |
| ITF M25 Jablonec Nad Nisou | 05/28 13:00 | 62 | Mikolaj Lis v Jonas P Hartenstein | 1-6,2-6 | |
| ITF M25 Praga | 05/16 08:00 | 62 | Jakob Schnaitter v Jonas P Hartenstein | Retired | |
| ITF M25 Praga | 05/15 10:45 | 62 | Tommy Czaplinski v Jonas P Hartenstein | 2-6,1-6 | |
| ITF M15 Orange Park | 05/02 14:00 | 19 | Jonas P Hartenstein v Jelani Sarr | 4-6,7-5,2-10 | |
| ITF M15 Boca Ratón | 11/15 14:00 | 54 | Jonas P Hartenstein v Martin Katz | 5-7,3-6 | |
| ITF M15 Boca Ratón | 11/14 14:00 | 54 | Jonas P Hartenstein v Liam Puttergill | 6-0,6-1 | |
| ITF M15 Tallahassee | 10/27 18:50 | 26 | Jonas P Hartenstein v Antoine C Chauvinc | 1-6,3-6 | |
| ITF M15 Tallahassee | 10/26 20:25 | 25 | Kyle Kang v Jonas P Hartenstein | 7-6,3-6,6-7 | |
| ITF M15 Tallahassee | 10/25 14:00 | 54 | Carles Hernandez v Jonas P Hartenstein | 6-1,4-6,4-10 | |
| ITF M15 Tallahassee | 10/24 14:00 | 54 | Alex Bulte v Jonas P Hartenstein | 3-6,6-3,11-13 | |
| ITF M15 Haren | 09/01 11:20 | 26 | Rafael Giotis v Jonas P Hartenstein | 6-3,3-6,7-5 | |
| ITF M15 Haren | 08/31 11:15 | 25 | Shinnosuke Hiramatsu v Jonas P Hartenstein | 3-6,4-6 | |
| ITF M15 Haren | 08/30 08:30 | 62 | Jonas P Hartenstein v Tomi Van den Ham | 6-2,6-4 |