Stadium: Court 5 Round: 14 Ground: Clay
| 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 Manama | 2021/11/23 11:40 | Johannes Haerteis v Alexander Erler | 6-3,6-4 |
| Challenger Eckental | 2021/11/02 13:15 | Henri Squire v Alexander Erler | 7-6,2-6,7-6 |
| Challenger Eckental | 2021/11/01 10:00 | Alexander Erler v Henri Squire | 4-6,2-6 |
| Challenger Eckental | 2021/10/31 10:35 | Alexander Erler v Artem Dubrivnyy | 6-1,6-3 |
| ATP Vienna | 2021/10/23 09:00 | Alexander Erler v Gianluca Mager | 7-6,2-6,4-6 |