Stadium: Court 3 Round: 54 Ground: Clay
| ITF M25 Wroclaw | 2021/06/28 13:00 | Lukas Pokorny v Carl Soderlund | 5-7,4-6 |
| ITF M25 Wroclaw | 2021/06/27 15:30 | Alan Bojarski v Lukas Pokorny | 2-6,2-6 |
| Challenger Bratislava | 2021/06/06 14:00 | Duje Ajdukovic v Lukas Pokorny | 6-1,7-6 |
| ITF M25 Most | 2021/05/23 08:00 | Niklas Rohrer v Lukas Pokorny | 7-6,6-3 |
| ITF M15 Antalya | 2021/05/09 07:00 | Gabriele Piraino v Lukas Pokorny | 4-6,6-2,10-7 |
| ITF M15 Sharm El Sheikh | 2021/04/07 08:30 | David Poljak v Lukas Pokorny | 6-3,6-3 |
| ITF M15 Sharm El Sheikh | 2021/04/06 07:30 | Karlo Cubelic v Lukas Pokorny | 6-7,1-6 |
| ITF M15 Sharm El Sheikh | 2021/04/05 07:30 | Lukas Pokorny v Shohei Chikami | 7-6,6-4 |
| ITF M25 Wroclaw | 2021/06/29 08:00 | Daniel Siniakov v Illya Beloborodko | 6-4,4-6,6-10 |
| ITF M25 Wroclaw | 2021/06/28 11:00 | Ignacio Monzon v Daniel Siniakov | 3-6,6-4,7-10 |
| ITF M25 Wroclaw | 2021/06/27 15:30 | Kamil Gajewski v Daniel Siniakov | 2-6,5-7 |
| Challenger Prostejov | 2021/06/15 08:30 | Daniel Siniakov v Sebastian Baez | 1-6,0-6 |
| ITF M25 Most | 2021/05/24 08:00 | Adan Freire Da Silva v Daniel Siniakov | 6-3,7-6 |
| ITF M25 Most | 2021/05/23 14:00 | Krystof Zapsky v Daniel Siniakov | 4-6,3-6 |
| ITF M25 Jablonec Nad Nisou | 2021/05/19 08:00 | Vitaliy Sachko v Daniel Siniakov | 4-6,6-3,6-4 |
| ITF M25 Prague | 2021/05/09 08:30 | Daniel Siniakov v Jakub Beran | 5-7,4-6 |