Stadium: BNP Paribas Court Round: 25 Ground: Clay
| ITF M25 Ueberlingen | 2021/08/17 15:00 | Mariano Kestelboim v Harrison, Ryan | 3-6,6-4,2-6 |
| ITF M25 Frankfurt am Main | 2021/08/13 09:50 | Mariano Kestelboim v Yshai Oliel | 2-6,2-6 |
| ITF M25 Frankfurt am Main | 2021/08/12 11:10 | Taiyo Yamanaka v Mariano Kestelboim | 2-6,2-6 |
| ITF M25 Frankfurt am Main | 2021/08/10 13:15 | Mariano Kestelboim v Valentin Royer | 6-4,7-6 |
| ITF M25 Wetzlar | 2021/08/04 08:00 | Mariano Kestelboim v Mats Rosenkranz | 5-7,2-6 |
| ITF M25 Gandia | 2021/07/24 15:00 | Antoine Escoffier v Mariano Kestelboim | 5-7,6-4,6-2 |
| ITF M25 Gandia | 2021/07/23 08:00 | Facundo Juarez v Mariano Kestelboim | 4-6,6-4,2-6 |
| ITF M25 Gandia | 2021/07/21 07:30 | Imanol L Morillo v Mariano Kestelboim | 7-5,3-6,4-6 |
| ITF M15 Allershausen | 2021/09/02 08:55 | Mats Rosenkranz v Niklas Schell | 6-3,7-6 |
| ITF M15 Allershausen | 2021/09/01 12:05 | Milan Welte v Niklas Schell | 6-3,2-6,3-6 |
| ITF M25 Ueberlingen | 2021/08/19 10:00 | Niklas Schell v Esteve Lobato, Eduard | 6-7,1-6 |
| ITF M25 Ueberlingen | 2021/08/18 09:30 | Niklas Schell v Florian Broska | 3-6,6-3,6-3 |
| ITF M25 Frankfurt am Main | 2021/08/10 10:30 | Taiyo Yamanaka v Niklas Schell | 6-1,6-2 |
| ITF M25 Frankfurt am Main | 2021/08/09 11:55 | Max Wiskandt v Niklas Schell | 6-3,3-6,5-10 |
| ITF M25 Marburg | 2021/07/07 13:00 | Louis Wessels v Niklas Schell | 6-3,6-4 |
| ITF M25 Klosters | 2021/06/20 08:55 | Zimmermann, Ilias v Niklas Schell | 6-4,4-6,12-10 |