Stadium: Court 5 Round: 27 Ground: Clay
| ITF M15 Szczawno | 2023/08/30 07:00 | Olaf Pieczkowski v Alan Bojarski | 6-0,6-2 |
| ITF M25 Poznan | 2023/08/23 13:45 | Olaf Pieczkowski v Viacheslav Bielinskyi | 6-3,3-6,2-6 |
| ITF M25 Bielsko Biala | 2023/08/18 08:30 | Juan Bautista Torres v Olaf Pieczkowski | 6-3,6-2 |
| ITF M25 Bielsko Biala | 2023/08/17 08:30 | Olaf Pieczkowski v Daniel Siniakov | 7-5,6-2 |
| ITF M25 Bielsko Biala | 2023/08/16 09:00 | Ondrej Horak v Olaf Pieczkowski | 6-3,1-6,0-6 |
| ITF M25 Lodz | 2023/08/10 10:30 | Daniel Paty v Olaf Pieczkowski | 6-3,6-2 |
| ITF M25 Lodz | 2023/08/09 09:20 | Milos Karol v Olaf Pieczkowski | 6-3,2-6,3-6 |
| ITF M25 The Hague | 2023/07/06 12:10 | Eric Vanshelboim v Olaf Pieczkowski | 6-0,6-4 |
| ITF M15 Szczawno | 2023/08/29 12:45 | Michal Mikula v Jonas P Hartenstein | 1-6,0-6 |
| ITF M25 Marburg | 2023/07/05 09:00 | Alex Rybakov v Jonas P Hartenstein | 6-4,6-0 |
| ITF M25 Marburg | 2023/07/04 08:00 | Jonas P Hartenstein v Martin Benes | 3-6,6-3,10-7 |
| ITF M25 Risskov/Aarhus | 2023/06/15 11:55 | Max Houkes v Jonas P Hartenstein | 6-7,6-4,6-3 |
| ITF M25 Risskov/Aarhus | 2023/06/14 10:40 | Olle Wallin v Jonas P Hartenstein | 2-6,4-6 |
| ITF M25 Jablonec Nad Nisou | 2023/05/30 10:15 | Peter Goldsteiner v Jonas P Hartenstein | 7-5,7-5 |
| ITF M25 Jablonec Nad Nisou | 2023/05/29 09:00 | Patrik Oplustil v Jonas P Hartenstein | 3-6,0-6 |
| ITF M25 Jablonec Nad Nisou | 2023/05/28 13:00 | Mikolaj Lis v Jonas P Hartenstein | 1-6,2-6 |