Stadium: Court 1 Round: 25 Ground: Hardcourt outdoor
| ITF W25 Sumter | 2021/06/14 13:00 | Erika Sema v Katja Wiersholm | 7-5,6-1 |
| ITF W25 Santo Domingo | 2021/05/30 17:00 | Mihaela Djakovic v Katja Wiersholm | 6-3,6-2 |
| ITF W15 Cancun | 2020/03/09 19:30 | Katja Wiersholm v Kariann Pierre-Louis | 1-6,1-6 |
| ITF W15 Cancun | 2020/03/09 17:00 | Madison Bourguignon v Katja Wiersholm | 6-7,3-6 |
| ITF W25 Daytona Beach | 2020/01/12 16:00 | Katja Wiersholm v Yuxuan Zhang | 2-6,3-6 |
| ITF W15 Oslo | 2019/10/21 07:00 | Liisa Vehvilainen v Katja Wiersholm | 6-3,4-6,11-9 |
| ITF W15 Oslo | 2019/10/20 08:00 | Magdalena Hedrzak v Katja Wiersholm | 1-6,1-6 |
| ITF W15 Lubbock | 2019/09/19 15:00 | Katja Wiersholm v Savannah Broadus | 6-3,5-7,4-6 |
| ITF W15 Monastir | 2021/07/14 11:20 | Chiraz Bechri v Katarina Kozarov | 4-6,6-1,6-3 |
| ITF W15 Monastir | 2021/07/11 13:00 | Katarina Kozarov v Valerie Quiceno | 6-4,6-2 |
| ITF W15 Monastir | 2021/06/20 08:30 | Katarina Kozarov v Mell E R Gonzalez | 6-7,6-3,4-6 |
| ITF W15 Monastir | 2021/06/18 11:15 | Kathleen Kanev v Katarina Kozarov | 6-4,0-6,3-6 |
| ITF W15 Monastir | 2021/06/17 11:30 | Sophia Biolay v Katarina Kozarov | 0-6,6-7 |
| ITF W15 Monastir | 2021/06/16 15:30 | Katarina Kozarov v Lamis Alhussein Abdel Aziz | 6-7,6-4,6-4 |
| ITF W15 Monastir | 2021/06/15 10:00 | Katarina Kozarov v Astrid Cirotte | 6-1,6-1 |
| ITF W15 Monastir | 2021/06/14 10:30 | Katarina Kozarov v Anastasia Kovaleva | 6-2,7-5 |