Stadium: Court 2 Round: 25 Ground: Hardcourt outdoor
| Davis Cup | 2021/11/27 10:10 | Elliot Benchetrit v Christian Sigsgaard | 7-6,3-6,6-2 |
| ITF M15 Doha | 2021/10/13 14:15 | Oscar Moraing v Christian Sigsgaard | 6-4,6-2 |
| ITF M15 Doha | 2021/10/08 12:30 | Christian Sigsgaard v Oscar Moraing | 6-3,1-6,2-6 |
| ITF M15 Doha | 2021/10/07 14:50 | Christian Sigsgaard v Boris Butulija | 6-1,6-3 |
| ITF M15 Doha | 2021/10/06 15:30 | Saketh Myneni v Christian Sigsgaard | 4-6,4-6 |
| ITF M25 Falun | 2021/09/29 14:50 | Antoine Escoffier v Christian Sigsgaard | 7-5,6-7,6-4 |
| ITF M25 Falun | 2021/09/28 12:45 | Leo Borg v Christian Sigsgaard | 3-6,4-6 |
| ITF M25 Falun | 2021/09/26 11:00 | Christian Sigsgaard v Jonathan Backman | 6-1,6-4 |
| Challenger Eckental | 2021/11/01 11:55 | Tobias Simon v Peter Heller | 6-2,6-4 |
| ITF M15 Antalya | 2021/10/26 08:25 | Peter Heller v Jack Pinnington Jones | 3-6,4-6 |
| Challenger Lisbon | 2021/09/27 09:00 | Santiago Rodriguez Taverna v Peter Heller | 7-6,7-5 |
| Challenger Lisbon | 2021/09/26 11:25 | Luis Faria v Peter Heller | 1-6,7-6,4-6 |
| Challenger Braga | 2021/09/21 09:00 | Thiago Monteiro v Peter Heller | 6-3,6-3 |
| Challenger Braga | 2021/09/19 09:00 | Miguel Gomes v Peter Heller | 0-6,1-6 |
| ITF M15 Allershausen | 2021/09/02 13:40 | Peter Heller v Guy Den Ouden | 6-7,3-6 |
| ITF M15 Allershausen | 2021/09/01 11:15 | Peter Heller v Henri Squire | 6-3,3-6,6-4 |