Stadium: Court Lisboa Round: 14 Ground: Clay
| Challenger Banja Luka | 2021/09/05 09:00 | Aldin Setkic v Marco Bortolotti | 7-5,6-4 |
| Challenger Barletta | 2021/08/22 10:00 | Nicolas Alvarez v Marco Bortolotti | 6-4,5-7,6-2 |
| Challenger Verona | 2021/08/17 10:20 | Pavel Kotov v Marco Bortolotti | 6-3,6-3 |
| ITF - Bolzano M25 | 2021/08/05 08:00 | Federico Arnaboldi v Marco Bortolotti | 6-3,6-3 |
| ITF - Bolzano M25 | 2021/08/04 11:10 | Marco Bortolotti v Arthur Reymond | 6-4,6-4 |
| ITF - Bolzano M25 | 2021/08/03 16:20 | Marco Bortolotti v Luca Castagnola | 6-1,3-6,6-2 |
| ITF - Wrocław M25 | 2021/06/30 11:15 | Marco Bortolotti v Illya Beloborodko | 3-6,3-6 |
| Challenger Biella | 2021/05/30 10:55 | Alexey Vatutin v Marco Bortolotti | 3-6,6-4,6-1 |
| Challenger Braga | 2021/09/20 09:00 | Nikolas Sanchez Izquierdo v Sebastian Fanselow | 6-4,1-6,6-3 |
| Challenger Braga | 2021/09/19 10:25 | Jaime Faria v Sebastian Fanselow | 0-6,2-6 |
| ITF - Sintra M25 | 2021/09/15 15:35 | Adria Soriano Barrera v Sebastian Fanselow | 6-4,6-4 |
| ITF - Sintra M25 | 2021/09/08 10:40 | Luca Potenza v Sebastian Fanselow | 6-4,6-4 |
| ITF - Bagneres-De-Bigorre M25 | 2021/09/01 07:30 | Millen Hurrion v Sebastian Fanselow | 2-6,7-5,7-6 |
| Challenger Poznań | 2021/07/25 10:30 | Sebastian Fanselow v Lucas Gerch | 2-6,5-7 |
| ITF - Bourg-en-Bresse M25 | 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 |