Stadium: Court 5 Round: 25 Ground: Clay
| ITF M15 Novomoskovsk | 2021/05/30 06:15 | Fellin, Manfred v Leyton Rivera | 4-6,6-3,6-10 |
| ITF M15 Novomoskovsk | 2021/05/23 10:30 | Alcalde, Juan Ignacio v Fellin, Manfred | 7-6,2-6,10-3 |
| ITF M15 Cairo | 2021/04/26 08:00 | Fellin, Manfred v Ragazzi, Alessandro | 3-6,1-6 |
| ITF M15 Cairo | 2021/04/21 09:25 | Capecchi, Daniele v Fellin, Manfred | 6-0,6-4 |
| ITF M15 Cairo | 2021/04/20 08:00 | Luigi Sorrentino v Fellin, Manfred | 6-2,6-2 |
| ITF M15 Cairo | 2021/04/18 17:30 | El Sayed, Ashraf v Fellin, Manfred | 0-6,3-6 |
| ITF M15 Cairo | 2021/04/13 12:30 | Kawakami, Rimpei v Fellin, Manfred | 6-4,6-0 |
| ITF M15 Cairo | 2021/04/12 08:30 | Garmendia Olasagasti, Inigo v Fellin, Manfred | 2-6,2-6 |
| ITF M25 Uriage | 2021/07/14 12:00 | Nathan Seateun v Giovanni Mpetshi Perricard | 4-6,2-6 |
| ITF M25 Montauban | 2021/06/24 13:30 | Oscar Jose Gutierrez v Nathan Seateun | 6-2,7-5 |
| ITF M25 Montauban | 2021/06/22 11:00 | Nathan Seateun v Eriksson, Markus | 6-4,7-5 |
| ITF - M25 La Nucia | 2021/03/14 11:00 | Nathan Seateun v Egor Matvievici | 6-2,6-0 |
| ITF M15 La Nucia | 2021/03/11 13:00 | Nathan Seateun v Nikolas Sanchez Izquierdo | 2-6,1-6 |
| ITF M15 La Nucia | 2021/03/10 12:42 | Miguel Damas v Nathan Seateun | 3-6,1-6 |
| ITF M15 La Nucia | 2021/03/10 10:30 | Miguel Damas v Nathan Seateun | 3-6,1-6 |
| ITF M15 La Nucia | 2021/03/09 15:45 | Nathan Seateun v Miguel Damas | 7-5,6-1 |