Stadium: Center Court Round: 54 Ground: Clay
| ITF W25 Marbella | 2020/09/01 08:00 | Sebastianna Scilipoti v Marthiens, Karen | 7-5,6-1 |
| ITF W25 Marbella | 2020/08/31 08:30 | Marthiens, Karen v Alba Rey Garcia | 6-4,7-5 |
| ITF W25 Marbella | 2020/08/30 13:00 | Nunez, Isabella v Marthiens, Karen | 3-6,0-6 |
| ITF W80 Poitiers | 2019/10/21 12:50 | Yerolymos, Margot v Marthiens, Karen | 6-2,6-1 |
| Andrezieux-Boutheon, Singles W-ITF-FRA-25A | 2019/09/30 08:00 | Marthiens, Karen v Nsimba, L. N. | 2-6,4-6 |
| Clermont-Ferrand, Singles W-ITF-FRA-24A | 2019/09/23 09:15 | Maelys Bougrat v Marthiens, Karen | 0-6,6-2,10-8 |
| Vitoria-Gasteiz, Singles W-ITF-ESP-14A | 2019/07/25 10:10 | Cristina Bucsa v Marthiens, Karen | 6-2,6-0 |
| Vitoria-Gasteiz, Singles W-ITF-ESP-14A | 2019/07/24 14:30 | Julieta Lara Estable v Marthiens, Karen | 3-6,7-6,1-6 |