Stadium: Court 3 Round: 14 Ground: Clay
| ITF Women Oslo | 2018/10/23 08:00 | Katharina Gerlach v Katarzyna Piter | 4-6,2-6 |
| ITF Women Horb | 2018/07/29 13:00 | Katarzyna Piter v Katharina Gerlach | 6-4,3-6,6-7 |
| WTA Bad Homburg | 2021/06/21 14:30 | Petra Kvitova v Katarzyna Piter | 4-6,6-1,6-4 |
| WTA Bad Homburg | 2021/06/20 09:00 | Katarzyna Piter v Nastasja Schunk | 7-6,2-6,7-6 |
| WTA Bogota | 2021/04/03 16:25 | Katarzyna Piter v Marina Melnikova | 5-7,0-6 |
| WTA Guadalajara | 2021/03/06 23:20 | Olga Govortsova v Katarzyna Piter | 6-0,6-2 |
| WTA Abu Dhabi | 2021/01/05 08:05 | Katarzyna Piter v Jessica Pieri | 4-6,0-6 |
| ITF W80 Tyler | 2020/10/26 19:20 | Mayo Hibi v Katarzyna Piter | 6-4,6-7,10-5 |
| ITF W60 Saint Malo | 2020/09/08 09:45 | Katarzyna Piter v Flavie Brugnone | 0-6,3-6 |
| Polish National Tour - nők | 2020/08/24 09:30 | Katarzyna Piter v Weronika Falkowska | 4-6,6-3,3-6 |
| Wimbledon - nők | 2021/06/22 18:05 | Katharina Gerlach v Astra Sharma | 4-6,0-6 |
| ITF W60 Stare Splavy | 2021/06/17 07:55 | Katharina Gerlach v Irene Burillo Escorihuela | 1-6,6-3,1-6 |
| ITF W25 Otocec -nők | 2021/06/04 09:25 | Iva Primorac v Katharina Gerlach | 6-4,6-4 |
| ITF W25 Otocec -nők | 2021/06/03 09:55 | Raluca Georgiana Serban v Katharina Gerlach | 2-6,3-6 |
| ITF W25 Otocec -nők | 2021/06/02 13:35 | Marie Benoit v Katharina Gerlach | 2-6,0-6 |
| ITF W60 Saint-Gaudens | 2021/05/12 07:00 | Anna Bondar v Katharina Gerlach | 6-3,6-3 |
| ITF W60 Saint-Gaudens | 2021/05/11 13:00 | Katharina Gerlach v Vlada Koval | 6-1,6-4 |
| ITF W60 Saint-Gaudens | 2021/05/10 15:30 | Katharina Gerlach v Estelle Cascino | 6-3,6-4 |