Stadium: Ahnatal C8 Round: 62 Ground: Clay
| ITF Germany F8 Qual | 2018/07/15 08:30 | Marcel Marlon Sudzum v Oscar Moraing | 6-2,6-4 |
| ITF Germany F7 | 2018/07/08 08:00 | Marcel Marlon Sudzum v Nicolas Zaidman | 4-6,0-6 |
| ITF Belgium F3 Qual | 2018/06/30 07:30 | Marcel Marlon Sudzum v Arnaud Destrebecq | 2-6,2-6 |
| ITF Belgium F2 Qual | 2018/06/24 11:00 | Alex Knaff v Marcel Marlon Sudzum | 6-1,2-6,6-4 |
| ITF Belgium F2 Qual | 2018/06/23 15:25 | Marcel Marlon Sudzum v Ian O'Jon | 6-2,6-4 |
| ITF Czech Republic F2 | 2018/05/23 11:40 | Marcel Marlon Sudzum v Robin Staněk | 2-6,5-7 |
| ITF Czech Republic F2 Qual | 2018/05/21 11:30 | Yvo Panak v Marcel Marlon Sudzum | 3-6,4-6 |
| ITF Czech Republic F2 Qual | 2018/05/20 10:00 | Marcel Marlon Sudzum v David Juras | 6-1,6-3 |
| ITF Germany F8 Qual | 2018/07/15 08:30 | Marlon Vankan v Niklas Guttau | 1-6,2-6 |
| Challenger Braunschweig Qual | 2018/07/07 09:30 | Kimmer Coppejans v Niklas Guttau | 6-3,6-1 |
| ITF Germany F4 | 2018/06/19 10:45 | Wilfredo Gonzalez v Niklas Guttau | 6-3,7-6 |
| ITF Turkey F15 | 2018/04/14 07:30 | Niklas Guttau v Louroi Martinez | 1-6,6-2,0-6 |
| ITF Turkey F14 | 2018/04/07 11:00 | Niklas Guttau v Lucas Hellfritsch | 4-6,3-6 |
| ITF Turkey F13 | 2018/03/31 11:00 | Felipe Meligeni Rodrigues Alves v Niklas Guttau | 6-3,6-1 |
| ITF Tunisia F32 | 2017/10/23 08:30 | Francois-Arthur Vibert v Niklas Guttau | 6-1,6-2 |
| ITF Tunisia F32 | 2017/10/22 08:30 | Matt McBride v Niklas Guttau | 3-6,3-6 |