Stadium: Court 1 Round: 62 Ground: Clay
| ITF M15 Cairo | 2021/08/02 11:30 | Ivanov, Vladislav v Sigurdsson, Egill | 6-2,6-4 |
| ITF M15 Cairo | 2021/07/28 12:25 | Sigurdsson, Egill v Lorenzo Bocchi | 0-6,3-6 |
| ITF M15 Cairo | 2021/07/19 10:30 | Nicolas Hollender v Sigurdsson, Egill | 6-1,3-6,10-6 |
| ITF M15 Cairo | 2021/07/18 13:00 | Sergo Sikharulidze v Sigurdsson, Egill | 4-6,6-3,8-10 |
| Coupe Davis | 2021/06/19 09:35 | Sigurdsson, Egill v Raphael Calzi | 4-6,0-6 |
| Coupe Davis | 2021/06/17 09:30 | Petros Chrysochos v Sigurdsson, Egill | 6-1,6-0 |
| Coupe Davis | 2021/06/16 09:20 | Aleksandre Metreveli v Sigurdsson, Egill | 6-0,6-3 |
| ITF M15 Cairo | 2021/05/02 08:00 | de Rosa, Marco v Sigurdsson, Egill | 4-6,6-4,10-7 |
| Hamburg, Germany | 2021/07/10 09:00 | Carlos Taberner v Guttau, Niklas | 6-1,6-2 |
| ITF - M15 Antalya | 2021/04/11 07:00 | Graziani, Edoardo v Guttau, Niklas | 6-4,6-1 |
| ITF - M15 Antalya | 2021/04/06 07:00 | Guttau, Niklas v Graziani, Edoardo | 2-6,3-6 |
| ITF - M15 Antalya | 2021/04/05 07:00 | Guttau, Niklas v Tomas Lanik | 6-2,6-2 |
| ITF - M15 Antalya | 2021/04/04 06:30 | Guttau, Niklas v Michel Hopp | 6-1,6-3 |
| ITF - M15 Sharm El Sheikh | 2021/03/16 10:10 | Guttau, Niklas v Liu, Shao-Fan | 3-6,6-1,4-10 |
| ITF - M15 Sharm El Sheikh | 2021/03/15 11:30 | Guttau, Niklas v Lorenzo Rottoli | 6-3,6-1 |
| ITF - M15 Sharm El Sheikh | 2021/03/14 14:30 | Guttau, Niklas v Babji Siva Atturu | 6-0,6-2 |