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