Estadio: Center Court Round: 19 Ground: Clay
| ITF W60 Wiesbaden | 2019/05/01 12:10 | Katharina Gerlach v Anna Zaja | 4-6,6-3,0-6 |
| ITF Shrewsbury - Femenino | 2018/11/06 14:15 | Katharina Gerlach v Anna Zaja | 4-6,4-6 |
| WTA Núremberg - Clasificación | 2018/05/19 13:05 | Katharina Gerlach v Anna Zaja | 6-7,3-6 |
| WTA Hamburgo | 2021/07/05 08:00 | Magdalena Frech v Anna Zaja | 0-0 |
| WTA Hamburgo | 2021/07/05 08:00 | Jasmin Jebawy v Anna Zaja | 2-6,3-6 |
| WTA Bad Homburg | 2021/06/21 11:30 | Anna Zaja v Ann Li | 0-6,4-6 |
| WTA Bad Homburg | 2021/06/20 09:00 | Anna Zaja v Julia Middendorf | 6-2,7-5 |
| ITF W25 Jönköping | 2021/06/16 11:10 | Carol Zhao v Anna Zaja | 6-4,4-6,6-2 |
| ITF W25 Jönköping | 2021/06/15 08:10 | Joanne Zuger v Anna Zaja | 5-7,4-6 |
| ITF W25 Liepaja | 2021/05/29 08:00 | Anna Zaja v Daniela Vismane | 6-1,3-6,4-6 |
| ITF W25 Liepaja | 2021/05/28 14:00 | Anna Zaja v Kamilla Bartone | 6-0,6-2 |
| WTA Hamburgo | 2021/07/05 08:00 | Katarzyna Piter v Katharina Gerlach | 2-6,5-7 |
| Wimbledon - Femenino | 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 | 2021/06/04 09:25 | Iva Primorac v Katharina Gerlach | 6-4,6-4 |
| ITF W25 Otocec | 2021/06/03 09:55 | Raluca Georgiana Serban v Katharina Gerlach | 2-6,3-6 |
| ITF W25 Otocec | 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 |