Stadium: Court 4 Round: 54 Ground: Hardcourt indoor
| German Championship - Kvinder | 2021/12/05 13:00 | Chiara Tomasetti v Karla Bartel | 6-7,6-2,0-0 |
| ITF W25 - Santa Margherita | 2023/09/25 10:25 | Laura Hietaranta v Anna Klasen | 6-2,6-3 |
| ITF W60 - Wien | 2023/09/04 09:00 | Chiara Scholl v Anna Klasen | 6-2,6-2 |
| ITF W40 - Oldenzaal | 2023/08/30 16:50 | Merel Hoedt v Anna Klasen | 6-2,6-1 |
| ITF W40 - Oldenzaal | 2023/08/29 07:30 | Marine Partaud v Anna Klasen | 6-4,4-6,4-6 |
| ITF W40 - Oldenzaal | 2023/08/28 08:00 | Emma Van Poppel v Anna Klasen | 2-6,0-6 |
| ITF W25 - Braunschweig | 2023/08/22 11:05 | Anna Klasen v Ella Seidel | 2-6,3-6 |
| ITF W40 - Ystad | 2023/06/19 08:10 | Anna Klasen v Lia Karatancheva | 5-7,1-6 |
| ITF W60 - Ricany | 2023/06/12 10:50 | Nika Radisic v Anna Klasen | 6-3,6-2 |