Stadium: Court 2 Round: 19 Ground: Clay
| ITF M25 Angers | 2021/04/21 15:05 | Sebastian Fanselow v Nikolas Sanchez Izquierdo | 6-2,7-5 |
| Challenger Braga | 2021/09/19 11:50 | Nikolas Sanchez Izquierdo v Henrique Rocha | 6-2,7-5 |
| ITF M25 Madrid | 2021/09/18 12:30 | Luca Nardi v Nikolas Sanchez Izquierdo | 7-5,6-3 |
| ITF M25 Madrid | 2021/09/17 10:45 | Nikolas Sanchez Izquierdo v Filip Misolic | 6-3,6-2 |
| ITF M25 Madrid | 2021/09/16 10:20 | Nikolas Sanchez Izquierdo v Arnaud Bovy | 7-5,6-3 |
| ITF M25 Madrid | 2021/09/15 10:20 | Facundo Diaz Acosta v Nikolas Sanchez Izquierdo | 3-6,3-6 |
| ITF M25 Madrid | 2021/09/14 09:05 | Nikolas Sanchez Izquierdo v Constantinos Koshis | 6-2,6-2 |
| ITF M25 Madrid | 2021/09/13 09:00 | Nikolas Sanchez Izquierdo v Vojtech Vlkovsky | 6-4,6-4 |
| Challenger Seville selejtezők | 2021/09/06 11:00 | Nikolas Sanchez Izquierdo v Tomas Barrios Vera | 6-4,2-6,5-7 |
| Challenger Braga | 2021/09/19 10:25 | Jaime Faria v Sebastian Fanselow | 0-6,2-6 |
| ITF M25 Sintra | 2021/09/15 15:35 | Adria Soriano Barrera v Sebastian Fanselow | 6-4,6-4 |
| ITF M25 Sintra | 2021/09/08 10:40 | Luca Potenza v Sebastian Fanselow | 6-4,6-4 |
| ITF M25 Bagneres-De-Bigorre | 2021/09/01 07:30 | Millen Hurrion v Sebastian Fanselow | 2-6,7-5,7-6 |
| Challenger Poznan | 2021/07/25 10:30 | Sebastian Fanselow v Lucas Gerch | 2-6,5-7 |
| ITF M25 Bourg-en-Bresse | 2021/06/29 13:00 | Viktor Durasovic v Sebastian Fanselow | 1-6,7-6,6-2 |
| Challenger Milan | 2021/06/20 13:15 | Sebastian Fanselow v Camilo Ugo Carabelli | 6-3,2-6,2-6 |
| Challenger Forli | 2021/06/15 09:30 | Sebastian Fanselow v Camilo Ugo Carabelli | 2-6,2-6 |