Stadium: Court 2 Round: 54 Ground: Carpet indoor
| ITF M15 Monastir | 2021/09/12 09:00 | Mattias Southcombe v Alex Knaff | 2-6,7-6,10-7 |
| ITF M15 Monastir | 2021/09/06 11:00 | Alex Knaff v Masamichi Imamura | 6-2,3-6,3-10 |
| ITF M15 Monastir | 2021/09/05 11:00 | Tom Dynka v Alex Knaff | 0-6,0-6 |
| ITF M15 Monastir | 2021/09/01 11:05 | Alex Knaff v Felix Corwin | 7-5,6-7,3-6 |
| ITF M15 Monastir | 2021/08/31 08:00 | Yuta Kawahashi v Alex Knaff | 7-5,4-6,7-10 |
| ITF M15 Monastir | 2021/08/30 13:00 | Alex Knaff v Egor Tsarapkin | 6-3,6-3 |
| ITF M25 Trier | 2021/08/23 14:45 | Yannik Steinegger v Alex Knaff | 6-3,6-1 |
| ITF M25 Trier | 2021/08/23 09:00 | Alex Knaff v Jeremy Schifris | 6-3,7-6 |
| UTR Pro Tennis Series Mulheim | 2021/09/25 07:00 | Julien De Cuyper v Lawrence Bataljin | 0-6,0-6 |
| UTR Pro Tennis Series Mulheim | 2021/09/24 13:30 | George Botezan v Julien De Cuyper | 6-4,6-1 |
| UTR Pro Tennis Series Mulheim | 2021/09/23 12:30 | Pablo Carretero v Julien De Cuyper | 6-3,6-3 |
| UTR Pro Tennis Series Mulheim | 2021/09/22 11:00 | Jing L Weng v Julien De Cuyper | 6-1,5-4 |
| ITF M25 Plaisir | 2021/09/12 07:55 | Liova Ajavon v Julien De Cuyper | 3-6,6-2,10-6 |
| UTR Pro Tennis Series Sofia | 2021/09/01 09:30 | Milen Ianakiev v Julien De Cuyper | 6-3,5-1 |
| UTR Pro Tennis Series Sofia | 2021/08/31 09:30 | Yurii Dzhavakian v Julien De Cuyper | 6-0,5-0 |
| UTR Pro Tennis Series Sofia | 2021/08/30 11:30 | Julien De Cuyper v Alexander Lazov | 2-6,2-5 |