Stadium: Court 4 Round: 62 Ground: Clay
| Challenger Luedenscheid | 2021/08/15 14:10 | Jonas Forejtek v Julius Seifert | 6-2,6-1 |
| ITF M25 Hammamet | 2024/02/12 08:30 | Daniel Bagnolini v Ruben Hartig | 6-3,6-0 |
| ITF M15 Antalya | 2023/12/17 07:00 | Hien Q H Pham v Ruben Hartig | 6-4,7-6 |
| ITF M15 Antalya | 2023/12/10 07:00 | Pablo Roche Alcaya v Ruben Hartig | 7-6,6-3 |
| German Championship | 2023/12/03 16:00 | Sebastian Gampert v Ruben Hartig | 6-2,6-3 |
| ITF M25 Monastir | 2023/11/12 08:00 | Ruben Hartig v Teymuraz Gabashvili | 2-6,0-6 |
| ITF M25 Monastir | 2023/11/06 09:30 | Toby Martin v Ruben Hartig | 6-1,6-1 |
| ITF M25 Monastir | 2023/11/05 08:00 | Ruben Hartig v Nicholas Van Aken | 6-2,6-1 |
| ITF M15 Monastir | 2023/10/23 15:00 | Ruben Hartig v Jaka Protic Zakelj | 1-6,3-6 |