Ground: Hardcourt outdoor
| UTR Pro Tennis Series Zadar | 2021/11/19 09:00 | Deni Zmak v Christos Keisidis | 6-1,6-0 |
| UTR Pro Tennis Series Zadar | 2021/11/18 10:30 | Christos Keisidis v Alexander Chepik | 6-3,6-2 |
| UTR Pro Tennis Series Zadar | 2021/11/16 09:00 | Christos Keisidis v Denis Parshutin | 6-3,6-7,6-3 |
| UTR Pro Tennis Series Zadar | 2021/11/15 12:00 | Olexiy Kolisnyk v Christos Keisidis | 7-5,3-6,4-6 |
| UTR Pro Tennis Series Nis | 2021/10/10 08:00 | Christos Keisidis v Vladimir Popov | 6-1,5-2 |
| UTR Pro Tennis Series Nis | 2021/10/09 11:00 | Christos Keisidis v Lawrence Bataljin | 6-4,6-2 |
| UTR Pro Tennis Series Nis | 2021/10/08 15:45 | Dusan Trunic v Christos Keisidis | 2-6,2-5 |
| UTR Pro Tennis Series Nis | 2021/10/07 08:30 | George Botezan v Christos Keisidis | 6-3,6-3 |