Stadium: Court 2 Round: 25 Ground: Clay
| ITF M15 - Kazan | 2021/03/09 06:55 | Koray Kirci v Daniel Ibragimov | 4-6,6-7 |
| ITF M15 - Kazan | 2021/03/08 10:20 | Koray Kirci v Roman Nashatyrkin | 6-3,7-6 |
| ITF - M15 Antalya | 2021/02/24 10:00 | Koray Kirci v Dragos Nicolae Madaras | 2-6,0-6 |
| ITF - M15 Antalya | 2021/02/07 06:00 | Dan Alexandru Tomescu v Koray Kirci | 6-3,6-1 |
| Challenger - Istanbul | 2021/01/17 08:45 | Koray Kirci v Ramkumar Ramanathan | 3-6,2-6 |
| Eastern European Championship | 2020/11/20 12:30 | Bart Stevens v Koray Kirci | 6-4,6-1 |
| Eastern European Championship | 2020/11/19 12:55 | Jaimee Floyd Angele v Koray Kirci | 6-4,6-2 |
| Eastern European Championship | 2020/11/18 10:55 | Duje Kekez v Koray Kirci | 6-4,2-6,4-6 |
| ITF - M15 Antalya | 2021/03/16 07:00 | Guy Den Heijer v Giovanni Rizzuti | 7-5,6-2 |
| ITF - M15 Antalya | 2021/03/15 08:30 | Guy Den Heijer v Juan Ignacio Alcalde | 6-1,6-1 |
| ITF - M15 Antalya | 2021/03/14 07:00 | Guy Den Heijer v Andrea Gola | 6-1,6-3 |
| ITF - M15 Antalya | 2021/03/07 07:00 | Guy Den Heijer v Michalis Sakellaridis | 2-6,3-6 |
| ITF - M15 Antalya | 2021/02/08 07:00 | Guy Den Heijer v Benedikt Henning | 3-6,0-6 |
| ITF - M15 Antalya | 2021/02/07 06:00 | Guy Den Heijer v Sidane Pontjodikromo | 7-5,2-6,10-8 |
| ITF - M15 Antalya | 2021/02/01 11:00 | Guy Den Heijer v Leopold Zima | 4-6,3-6 |
| ITF - M15 Antalya | 2021/01/29 07:00 | Timur Kiyamov v Guy Den Heijer | 4-6,3-6 |