Stadium: Court 3 Round: 25 Ground: Hardcourt indoor
| ITF M25 - Jönköping | 2021/09/21 14:45 | Shintaro Imai v Leo Borg | 6-3,6-2 |
| Challenger Poznan | 2021/07/27 14:00 | Leo Borg v Alexander Shevchenko | 5-7,2-6 |
| Challenger Tampere | 2021/07/20 13:30 | Nicolas Kicker v Leo Borg | 6-3,6-0 |
| ATP Båstad | 2021/07/11 13:40 | Francisco Cerundolo v Leo Borg | 6-3,6-1 |
| UTR Pro Tennis Series - Köpenhamn | 2021/06/15 12:30 | Sebastian Grundtvig Jorgensen v Leo Borg | 6-3,5-2 |
| ITF M15 - Antalya | 2021/05/19 07:20 | Nicolas Moreno De Alboran v Leo Borg | 6-1,6-1 |
| ITF M15 - Antalya | 2021/05/13 10:15 | Leo Borg v Timofey Skatov | 2-6,1-6 |
| ITF M15 - Antalya | 2021/05/11 10:10 | Leo Borg v Fermin Tenti | 7-6,6-0 |
| ITF M25 - Falun | 2021/09/26 11:00 | Christian Sigsgaard v Jonathan Backman | 6-1,6-4 |
| 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 |