Stadium: Court 1 Round: 27 Ground: Clay
| ITF M25 Meerbusch | 2021/04/15 10:00 | Eriksson, Markus v Milan Welte | 3-6,1-6 |
| ITF M25 Meerbusch | 2021/04/14 12:15 | Milan Welte v Rondoni, Pietro | 6-3,4-6,6-4 |
| ITF M25 Meerbusch | 2021/04/13 13:30 | Mats Rosenkranz v Milan Welte | 2-6,2-6 |
| ITF M25 Meerbusch | 2021/04/12 11:00 | Hendrik Jebens v Milan Welte | 5-7,1-6 |
| ITF M25 Meerbusch | 2021/04/11 13:30 | Rother, Jannik v Milan Welte | 2-6,2-6 |
| ITF M25 Biel | 2021/03/29 13:35 | Milan Welte v Jakub Paul | 4-6,1-6 |
| ITF - M15 Rovinj | 2021/03/16 09:00 | Milan Welte v Federico Arnaboldi | 2-6,2-6 |
| ITF - M15 Rovinj | 2021/03/15 11:30 | Prechtel, Sebastian v Milan Welte | 6-1,4-6,1-10 |
| ITF M25 Meerbusch | 2021/04/15 10:00 | Erler, Alexander v Mertens, Yannick | 6-3,3-6,6-1 |
| ITF M25 Meerbusch | 2021/04/14 10:30 | Erler, Alexander v Netuschil, Marvin | 6-3,6-2 |
| ITF M25 Biel | 2021/03/30 08:00 | Erler, Alexander v Kilian Feldbausch | 4-6,6-3,5-10 |
| ITF M25 Biel | 2021/03/29 08:00 | Erler, Alexander v Mischa Lanz | 6-3,6-4 |
| Challenger - Lugano | 2021/03/21 11:50 | van Rijthoven, Tim 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 |