Stadium: Court 1 Round: 54 Ground: Hardcourt indoor
| ITF M25 Biel | 2021/03/29 08:00 | Erler, Alexander v Mischa Lanz | 6-3,6-4 |
| Challenger - Lugano | 2021/03/21 11:50 | Tim Van Rijthoven v Erler, Alexander | 7-6,6-0 |
| ITF - M25 Trimbach | 2021/03/12 09:55 | Elmar Ejupovic v Erler, Alexander | 7-6,6-7,6-3 |
| ITF - M25 Trimbach | 2021/03/11 10:00 | Quentin Folliot v Erler, Alexander | 4-6,3-6 |
| ITF - M25 Trimbach | 2021/03/09 14:40 | Yannik Steinegger v Erler, Alexander | 4-6,4-6 |
| ITF M15 Bratislava | 2021/03/03 09:00 | Briand, Jurgen v Erler, Alexander | 6-7,7-6,7-5 |
| ITF - M15 Monastir | 2021/02/26 11:15 | Erler, Alexander v Lilian Marmousez | 5-7,2-6 |
| ITF - M15 Monastir | 2021/02/25 07:55 | Erler, Alexander v Colin Sinclair | 7-6,5-7,6-1 |
| ITF M25 Biel | 2021/03/29 07:55 | Kilian Feldbausch v Kai Wehnelt | 3-6,6-1,11-9 |
| ITF - M25 Trimbach | 2021/03/08 12:50 | Niklas Schell v Kilian Feldbausch | 6-3,6-4 |