Stadium: Court 1 Round: 25 Ground: Clay
| Challenger Ismaning | 2018/10/17 12:30 | Alexander Erler v Lukas Klein | 3-6,4-6 |
| Challenger Biel | 2022/03/20 13:55 | Andrew Paulson v Alexander Erler | 7-5,6-3 |
| Challenger Bengaluru Qual | 2022/02/13 08:40 | Dominik Palan v Alexander Erler | 7-6,4-6,6-3 |
| Challenger Bengaluru | 2022/02/07 06:05 | Arjun Kadhe v Alexander Erler | 6-3,6-4 |
| Challenger Bengaluru | 2022/02/06 10:40 | Manish Sureshkumar v Alexander Erler | 2-6,4-6 |
| Challenger Forli Qual | 2022/01/16 12:55 | Alexander Erler v Lucas Miedler | 1-6,3-6 |
| Challenger Maia | 2021/12/14 14:40 | Alexander Erler v Fabian Marozsan | 1-6,2-6 |
| Challenger Forli | 2021/12/06 15:25 | Alexander Erler v Vitaliy Sachko | 6-3,2-6,2-6 |
| Challenger Forli | 2021/11/28 12:00 | Alexander Erler v Valentin Vacherot | 3-6,2-6 |
| Challenger Murcia | 2022/04/07 11:30 | Lukas Klein v Jonas Forejtek | 3-6,5-7 |
| Challenger Murcia | 2022/04/06 09:00 | Andrea Pellegrino v Lukas Klein | 3-6,6-1,3-6 |
| Challenger Marbella | 2022/03/29 09:00 | Nicolas Alvarez Varona v Lukas Klein | 7-6,6-4 |
| Challenger Marbella | 2022/03/28 08:00 | Lukas Klein v Alvaro Lopez San Martin | 6-3,6-4 |
| Challenger Marbella | 2022/03/27 10:20 | Lukas Klein v Titouan Droguet | 6-4,6-3 |
| Challenger Biel | 2021/09/22 09:00 | Lukas Klein v Mats Moraing | 7-5,4-6,4-6 |
| Challenger Warsaw | 2021/08/28 08:00 | Lukas Klein v Javier Barranco Cosano | 6-3,3-6,4-6 |
| Challenger Warsaw | 2021/08/26 11:00 | Lukas Klein v Andrey Kuznetsov | 7-5,6-1 |