Stadium: Court 1 Round: 25 Ground: Clay
| ITF M25 Frankfurt am Main | 2021/08/09 14:10 | Milan Welte v Taiyo Yamanaka | 6-7,4-6 |
| ITF M15 Parnu | 2021/08/04 09:20 | Vladimir Ivanov v Milan Welte | 7-5,1-6,6-3 |
| ITF M25 Marburg | 2021/07/09 12:00 | Ryan Nijboer v Milan Welte | 4-6,6-3,6-1 |
| ITF M25 Marburg | 2021/07/08 08:55 | Milan Welte v Neo Niedner | 6-2,6-1 |
| ITF M25 Marburg | 2021/07/07 12:30 | Daniel Cukierman v Milan Welte | 4-6,4-6 |
| ITF M25 Marburg | 2021/07/06 15:00 | Milan Welte v Raphael Collignon | 7-6,6-3 |
| ITF M25 Marburg | 2021/07/05 13:05 | Milan Welte v Christopher Patzanovsky | 6-1,6-3 |
| ITF M15 Heraklion | 2021/05/17 07:00 | Milan Welte v Tom Gentzsch | 6-0,6-3 |
| ITF M15 Cairo | 2021/08/05 09:20 | Lukas Krainer v Constantin Bittoun Kouzmine | 6-1,6-2 |
| ITF M15 Cairo | 2021/08/04 07:30 | Gabriele Maria Noce v Constantin Bittoun Kouzmine | 0-6,6-3,4-6 |
| ITF M15 Cairo | 2021/08/03 07:30 | Constantin Bittoun Kouzmine v Thiago Cigarran | 6-1,4-6,10-8 |
| ITF M15 Cairo | 2021/08/02 08:30 | Constantin Bittoun Kouzmine v Tobias Franco | 6-2,6-0 |
| ITF M15 Cairo | 2021/08/01 09:00 | Constantin Bittoun Kouzmine v Edoardo Zanada | 6-3,4-6,10-8 |
| ITF M15 Cairo | 2021/07/26 08:00 | Constantin Bittoun Kouzmine v Samuele Pieri | 6-7,3-6 |
| ITF M15 Cairo | 2021/07/25 08:00 | Constantin Bittoun Kouzmine v Ashraf El Sayed | 6-0,6-1 |
| ITF M15 Cairo | 2021/07/22 08:00 | Constantin Bittoun Kouzmine v Oleksandr Ovcharenko | 4-6,2-6 |