Stadium: Court 7 Round: 26 Ground: Clay
| ITF M15 - Frederiksberg | 2021/08/03 09:45 | Christian Sigsgaard v Giorgio Ricca | 6-3,6-3 |
| ITF M15 - Vejle | 2021/07/29 14:35 | Henrik Heise Korsgaard v Christian Sigsgaard | 7-5,6-2 |
| ITF M15 - Vejle | 2021/07/28 12:50 | Christian Sigsgaard v Ryan Nijboer | 6-3,6-2 |
| ITF M15 - Heraklion | 2021/05/31 06:30 | Christian Sigsgaard v Sean Hodkin | 2-6,7-5,6-10 |
| ITF M15 - Heraklion | 2021/05/30 09:00 | Matic Dimic v Christian Sigsgaard | 3-6,2-6 |
| ITF M15 - Tbilisi | 2021/05/22 06:00 | Christian Sigsgaard v Alexander Shevchenko | 6-7,6-7 |
| ITF M15 - Tbilisi | 2021/05/21 06:00 | Christian Sigsgaard v Benjamin Lock | 7-5,6-1 |
| ITF M15 - Tbilisi | 2021/05/20 06:00 | Christian Sigsgaard v Yurii Dzhavakian | 6-2,6-4 |
| ITF M15 - Frederiksberg | 2021/08/03 09:20 | Daniel De Jonge v Patrick Kypson | 6-3,7-6 |
| ITF M25 - Marburg | 2021/07/05 12:05 | Patrick Zahraj v Daniel De Jonge | 6-3,6-2 |
| ITF M25 - Haag | 2021/07/01 07:30 | Marko Tepavac v Daniel De Jonge | 7-5,6-1 |
| ITF M25 - Haag | 2021/06/27 08:00 | Max Van Wijk v Daniel De Jonge | 2-6,0-6 |
| UTR Pro Tennis Series - København | 2021/06/20 09:30 | Daniel De Jonge v Sebastian Grundtvig Jorgensen | 6-4,4-6,2-6 |
| UTR Pro Tennis Series - København | 2021/06/19 10:00 | Daniel De Jonge v Marius Ruzgas | 3-6,7-6,6-1 |
| UTR Pro Tennis Series - København | 2021/06/18 09:30 | Daniel De Jonge v Jesper Klov Nilsson | 6-3,4-6,6-3 |
| UTR Pro Tennis Series - København | 2021/06/17 08:00 | Daniel De Jonge v Nikolaj Katic | 4-6,6-4,6-0 |