Stadium: Clay 4 Round: 26 Ground: Clay
| ITF W80 Poitiers | 2021/10/26 14:15 | Simona Waltert v Marthiens, Karen | 6-0,6-1 |
| ITF W25 Cherbourg | 2021/10/06 08:25 | Marthiens, Karen v Himari Sato | 6-3,3-6,0-6 |
| ITF W25 Cherbourg | 2021/10/04 08:30 | Fiona Ganz v Marthiens, Karen | 6-2,6-1 |
| ITF W25 Cherbourg | 2021/10/03 10:15 | Galvao Borges, Mariana v Marthiens, Karen | 0-6,1-6 |
| ITF W15 Dijon | 2021/09/14 11:00 | Marthiens, Karen v Anna Klasen | 1-6,1-6 |
| ITF W15 Amarante | 2021/07/20 16:00 | Marthiens, Karen v Ayla Aksu | 2-6,3-6 |
| ITF W60 Vitoria-Gasteiz | 2021/07/12 10:00 | Pulchartova, Laetitia v Marthiens, Karen | 7-5,6-4 |
| ITF W60 Vitoria-Gasteiz | 2021/07/11 09:20 | Haseth, Lilly Elida v Marthiens, Karen | 4-6,6-4,7-10 |
| ITF - W15 Héraklion | 2021/11/03 07:00 | Rajkovic, Adriana v Ellie Logotheti | 6-2,7-5 |
| ITF - W15 Sharm El Sheikh | 2021/10/06 13:45 | Silvia Ambrosio v Rajkovic, Adriana | 6-2,6-2 |
| ITF W25 Vienna | 2021/08/30 09:30 | Martyna Kubka v Rajkovic, Adriana | 6-3,4-6,10-8 |
| ITF W25 Vienna | 2021/08/29 14:00 | Rajkovic, Adriana v Eszter Meri | 7-5,1-6,11-9 |
| ITF W25 Vienna | 2021/08/29 07:30 | Rajkovic, Adriana v Saumya Vig | 6-1,6-1 |
| ITF W15 Wanfercee-Baulet | 2021/08/27 13:25 | Rajkovic, Adriana v Oleksandra Oliynykova | 1-6,5-7 |
| ITF W15 Wanfercee-Baulet | 2021/08/26 13:15 | Rajkovic, Adriana v Kimmelmann, Julia | 6-3,6-4 |
| ITF W15 Wanfercee-Baulet | 2021/08/24 07:30 | Anouk Koevermans v Rajkovic, Adriana | 2-6,2-6 |