| UTR Pro Tennis Series Copenhagen Women | 2021/05/25 11:00 | Koelzer, Romy v Phillippa Preugschat | 6-2,6-0 |
| UTR Pro Tennis Series Copenhagen Women | 2021/05/24 10:00 | Ekani, Irys v Koelzer, Romy | 1-6,4-5 |
| ITF - W15 Antalya | 2021/04/27 11:05 | Manca Pislak v Koelzer, Romy | 6-1,6-3 |
| ITF - W15 Antalya | 2021/04/20 07:00 | Koelzer, Romy v Polina Kudermetova | 5-7,4-6 |
| ITF - W15 Antalya | 2021/04/14 08:40 | Lee, So-Ra v Koelzer, Romy | 2-6,6-2,6-0 |
| ITF - W15 Héraklion | 2020/11/19 07:30 | Sapfo Sakellaridi v Koelzer, Romy | 3-6,2-6 |
| ITF - W15 Héraklion | 2020/11/18 07:30 | Kimchi, Shavit v Koelzer, Romy | 2-6,4-6 |
| ITF - W15 Héraklion | 2020/11/15 08:00 | Cadantu, Alexandra v Koelzer, Romy | 3-6,6-1,2-6 |
| UTR Pro Tennis Series Copenhagen Women | 2021/05/24 10:00 | Maja Radenkovic v Berta Passola | 6-7,4-5 |