| ITF M15 Heraklion | 2021/06/09 08:00 | Antonio Cayetano March v Christos Keisidis | 4-6,7-6,6-2 |
| ITF M15 Heraklion | 2021/06/08 06:30 | Sean Hodkin v Christos Keisidis | 6-4,5-7,4-10 |
| ITF M15 Heraklion | 2021/06/07 09:00 | Christos Keisidis v Alexander Gaponenko | 6-4,6-1 |
| ITF M15 Heraklion | 2021/06/06 11:00 | Michel-Alexandre Fortin v Christos Keisidis | 0-6,0-6 |
| ITF M15 Heraklion | 2021/05/31 06:30 | Mattia Bellucci v Christos Keisidis | 6-4,6-3 |
| ITF M15 Heraklion | 2021/05/24 06:30 | Christos Keisidis v William Griffith | 2-6,3-6 |
| ITF M15 Heraklion | 2021/05/23 08:00 | Matic Dimic v Christos Keisidis | 2-6,4-6 |
| ITF M15 Heraklion | 2021/05/19 06:30 | Christos Keisidis v Aristotelis Thanos | 2-6,2-6 |
| UTR Pro Tennis Series Pazardzhik | 2021/04/03 08:30 | Denislav Prodanov v Pierre Faivre | 0-6,1-6 |
| UTR Pro Tennis Series Pazardzhik | 2021/04/02 10:00 | Jules Marie v Denislav Prodanov | 6-1,6-0 |
| ITF Bulgaria F1 Qual | 2017/05/07 09:00 | Denislav Prodanov v Radoslav Shandarov | 0-6,6-2,6-7 |