Stadium: Court 2 Round: 44 Ground: Hardcourt indoor
| ITF M25 Arlon | 2023/06/26 08:00 | Can Ayral v Raphael Calzi | 3-6,2-6 |
| ITF M25 Marburg | 2023/07/04 09:25 | Philipp Pavlenko v Ruben Hartig | 6-4,3-6,10-3 |
| ITF M25 Marburg | 2023/07/03 08:00 | Ruben Hartig v Tim Heger | 7-5,1-6,10-8 |
| ITF M15 Kamen | 2023/06/28 14:55 | Ruben Hartig v Mats Rosenkranz | 6-7,2-6 |
| ITF M15 Kamen | 2023/06/26 14:00 | Ruben Hartig v Lukas Janousek | 6-4,6-1 |
| ITF M15 Kamen | 2023/06/26 10:00 | Jack Karlsson Winstrand v Ruben Hartig | 0-6,1-6 |
| ITF M15 Saarlouis | 2023/06/18 12:00 | Jeffrey Von Der Schulenburg v Ruben Hartig | 6-1,6-0 |
| ITF M25 Risskov/Aarhus | 2023/06/11 13:25 | Ruben Hartig v Gianluca Cadenasso | 4-6,2-6 |
| ITF M15 Constanta | 2023/05/29 11:00 | Nicolas Bruna v Ruben Hartig | 7-5,7-6 |