Stadium: Court 2 Round: 25 Ground: Clay
| ITF M25 Biel | 2021/03/30 08:00 | Alexander Erler v Kilian Feldbausch | 4-6,6-3,5-10 |
| ITF M25 Biel | 2021/03/29 08:00 | Alexander Erler v Mischa Lanz | 6-3,6-4 |
| Challenger Lugano | 2021/03/21 11:50 | Tim Van Rijthoven v Alexander Erler | 7-6,6-0 |
| ITF M25 Trimbach | 2021/03/12 09:55 | Elmar Ejupovic v Alexander Erler | 7-6,6-7,6-3 |
| ITF M25 Trimbach | 2021/03/11 10:00 | Quentin Folliot v Alexander Erler | 4-6,3-6 |
| ITF M25 Trimbach | 2021/03/09 14:40 | Yannik Steinegger v Alexander Erler | 4-6,4-6 |
| ITF M15 Bratislava | 2021/03/03 09:00 | Jurgen Briand v Alexander Erler | 6-7,7-6,7-5 |
| ITF M15 Monastir | 2021/02/26 11:15 | Alexander Erler v Lilian Marmousez | 5-7,2-6 |
| ITF M25 Meerbusch | 2021/04/13 11:30 | Marvin Netuschil v Mats Hermans | 6-4,6-1 |
| ITF M25 Meerbusch | 2021/04/12 13:00 | Marvin Netuschil v Patric Prinoth | 6-1,6-1 |
| ITF M25 Meerbusch | 2021/04/12 09:30 | Marvin Netuschil v Kai Lemstra | 6-2,6-3 |
| ITF M15 Antalya | 2021/03/03 06:50 | Miljan Zekic v Marvin Netuschil | 6-0,6-3 |
| ITF M15 Antalya | 2021/02/07 06:00 | Marvin Netuschil v Sandro Kopp | 5-7,4-6 |
| ITF M15 Antalya | 2021/01/31 06:30 | Marvin Netuschil v Gabriel Donev | 4-6,6-7 |
| ITF M25 Hamburg | 2020/10/20 10:00 | Marvin Netuschil v Camilo Ugo Carabelli | 2-6,2-6 |
| ITF M25 Hamburg | 2020/10/19 11:00 | Marvin Netuschil v Yan Sabanin | 7-6,6-2 |