Stadium: Court 1 Round: 25 Ground: Hardcourt indoor
| UTR Pro Tennis Series Mulheim | 2021/07/31 08:30 | Hazem Naw v Tim Sandkaulen | 6-4,7-6 |
| UTR Pro Tennis Series Mulheim | 2021/07/29 13:30 | Matthew Thomson v Tim Sandkaulen | 6-7,1-6 |
| UTR Pro Tennis Series Mulheim | 2021/07/29 07:00 | Billy Harris v Tim Sandkaulen | 6-7,3-6 |
| UTR Pro Tennis Series Mulheim | 2021/07/28 11:00 | Mark Wallner v Tim Sandkaulen | 6-7,5-6 |
| UTR Pro Tennis Series Mulheim | 2021/07/26 11:00 | Guy Den Heijer v Tim Sandkaulen | 7-5,6-3 |
| Challenger Braunschweig | 2021/07/05 09:30 | Tim Sandkaulen v Daniel Michalski | 3-6,5-7 |
| Challenger Braunschweig | 2021/07/04 09:00 | Kacper Zuk v Tim Sandkaulen | 6-2,3-6,6-7 |
| ITF USA F25 | 2018/09/15 17:30 | Alan Kohen v Tim Sandkaulen | 6-4,6-4 |
| ITF M25 Falun | 2021/09/28 10:55 | Leopold Zima v Marvin Moeller | 6-3,6-3 |
| ITF M25 Jonkoping | 2021/09/23 08:00 | Marvin Moeller v Viktor Durasovic | 7-5,3-6,4-6 |
| ITF M25 Jonkoping | 2021/09/22 09:45 | Marvin Moeller v Tibo Colson | 6-2,3-6,6-3 |
| ITF M25 Jonkoping | 2021/09/21 09:20 | Marvin Moeller v Harry Wendelken | 4-6,7-5,6-1 |
| ITF M25 Plaisir | 2021/09/16 07:55 | Vasil Kirkov v Marvin Moeller | 2-6,7-6,7-6 |
| ITF M25 Plaisir | 2021/09/14 10:50 | Lisandru Rodriguez v Marvin Moeller | 1-6,0-6 |
| ITF M25 Trier | 2021/08/28 15:00 | Tim Handel v Marvin Moeller | 7-5,2-6,6-2 |
| ITF M25 Trier | 2021/08/27 12:00 | Marvin Moeller v Mick Veldheer | 6-3,6-3 |