Stadium: Court 1 Round: 54 Ground: Hardcourt indoor
| Davis Cup | 2021/09/17 14:00 | Christian Sigsgaard v Wishaya Trongcharoenchaikul | 6-3,6-2 |
| ITF M15 Monastir | 2021/09/11 08:30 | Christian Sigsgaard v Gage Brymer | 4-6,4-6 |
| ITF M15 Monastir | 2021/09/10 09:45 | Masamichi Imamura v Christian Sigsgaard | 3-6,6-3,3-6 |
| ITF M15 Monastir | 2021/09/09 09:40 | Christian Sigsgaard v Stuart Parker | 1-6,6-2,6-1 |
| ITF M15 Monastir | 2021/09/08 14:00 | Peter Bertran v Christian Sigsgaard | 3-6,3-6 |
| ITF M15 Monastir | 2021/09/07 08:00 | Christian Sigsgaard v James Ibrahim | 6-2,6-1 |
| ITF M15 Monastir | 2021/09/05 11:00 | Christian Sigsgaard v Amaury Raynel | 6-1,6-2 |
| ITF M25 Frankfurt am Main | 2021/08/12 10:50 | Christian Sigsgaard v Daniel Dutra Da Silva | 6-7,3-6 |
| ITF M25 Jonkoping | 2021/09/20 09:10 | Robin Thour v Jonathan Backman | 6-4,4-6,10-6 |
| ITF M25 Jonkoping | 2021/09/19 08:00 | Jonathan Backman v Caspar Schuetze | 7-6,6-0 |