| Challenger Nur-Sultan | 2020/03/11 06:40 | Lukas Klein v Kimmer Coppejans | 6-3,4-6,1-6 |
| Challenger Nur-Sultan | 2020/03/10 05:00 | Rostislav Galfinger v Lukas Klein | 0-6,1-6 |
| ITF M15 Trnava | 2020/02/29 11:55 | Lukas Klein v Danylo Kalenichenko | 4-6,2-6 |
| ITF M15 Trnava | 2020/02/28 12:05 | Lukas Klein v Aldin Setkic | 6-2,5-7,6-4 |
| ITF M15 Trnava | 2020/02/27 13:30 | Lukas Klein v Jiri Lehecka | 4-6,6-2,6-3 |
| ITF M15 Trnava | 2020/02/25 11:30 | Lukas Klein v Tomas Vanko | 6-2,6-0 |
| Challenger Bergamo | 2020/02/17 15:35 | Andrea Arnaboldi v Lukas Klein | 7-6,6-4 |
| Challenger Cherbourg | 2020/02/10 11:45 | Lukas Klein v Jules Marie | 2-6,6-7 |