Stadium: Court 6 Round: 26 Ground: Hardcourt outdoor
| ITF M15 Sharm El Sheikh | 2021/10/20 13:40 | Leonardo Malgaroli v Lukas Krainer | 6-7,2-6 |
| ITF M15 Cairo | 2021/09/22 08:00 | Marco Miceli v Lukas Krainer | 6-1,6-2 |
| Challenger Tulln | 2021/09/05 09:00 | Benjamin Hassan v Lukas Krainer | 6-4,6-4 |
| ITF M15 Bad Waltersdorf | 2021/09/02 08:00 | Tomas Lipovsek Puches v Lukas Krainer | 6-3,6-1 |
| ITF M15 Bad Waltersdorf | 2021/09/01 10:30 | Lukas Krainer v Hans Peter Kaufmann | 6-3,6-4 |
| ITF M15 Bad Waltersdorf | 2021/08/29 09:35 | Timo Stodder v Lukas Krainer | 6-3,6-2 |
| ITF M15 Bad Waltersdorf | 2021/08/28 08:00 | Gabriel Decamps v Lukas Krainer | 2-6,3-6 |
| ITF M15 Bad Waltersdorf | 2021/08/27 09:25 | Lukas Krainer v Neil Oberleitner | 6-7,6-4,6-0 |
| ITF M15 Sharm El Sheikh | 2021/10/20 11:25 | Arjun Mahadevan v David Poljak | 1-6,1-6 |
| ITF M25 Praha | 2021/10/10 08:25 | Khumoyun Sultanov v David Poljak | 6-2,3-6,6-4 |
| ITF M25 Praha | 2021/10/09 08:30 | Tobias Simon v David Poljak | 6-7,4-6 |
| ITF M25 Praha | 2021/10/08 09:00 | David Poljak v Sanjar Fayziev | 6-4,6-2 |
| ITF M25 Praha | 2021/10/07 11:55 | David Poljak v Pavel Nejedly | 6-3,3-6,6-2 |
| ITF M25 Praha | 2021/10/06 15:20 | David Poljak v Leopold Zima | 6-4,6-1 |
| Challenger Sibiu | 2021/09/26 07:30 | Yan Bondarevskiy v David Poljak | 7-5,3-6,6-3 |
| Challenger București | 2021/09/19 09:45 | David Poljak v Uladzimir Ignatik | 4-6,1-6 |