Stadium: Clay 8 Round: 62 Ground: Hardcourt outdoor
| ITF Turkey F30 | 2018/09/30 07:30 | Besednikov, Oleg v Guttau, Niklas | 5-7,0-6 |
| ITF Turkey F30 | 2018/09/29 07:00 | Guttau, Niklas v Neil Oberleitner | 6-3,6-4 |
| ITF Netherlands F5 | 2018/08/19 10:00 | Guttau, Niklas v Bruna, Esteban | 3-6,4-6 |
| ITF Netherlands F4 | 2018/08/11 09:00 | Meuffels, Alban v Guttau, Niklas | 6-3,6-4 |
| ITF Poland F6 | 2018/08/07 11:25 | Andrzejczuk, Adrian v Guttau, Niklas | 6-2,6-1 |
| ITF Poland F6 Qual | 2018/08/06 08:00 | Guttau, Niklas v Mlazga, Krzysztof | 6-2,6-4 |
| ITF Poland F6 Qual | 2018/08/05 09:30 | Guttau, Niklas v Iftimie, Michele Lorenzo | 5-7,6-2,6-3 |
| ATP Hamburg Qual | 2018/07/21 12:45 | Jozef Kovalik v Guttau, Niklas | 6-0,6-1 |
| ITF Turkey F30 | 2018/09/30 09:30 | Panin, Igor v Vicentiu Andrei Niculescu | 1-6,1-6 |
| ITF Turkey F30 | 2018/09/29 07:00 | Vicentiu Andrei Niculescu v Podzimek, Floris | 6-4,6-2 |
| ITF Romania F13 | 2018/09/09 10:00 | Lucas Gerch v Vicentiu Andrei Niculescu | 6-4,6-2 |
| ITF Romania F12 | 2018/09/02 07:00 | Manole, Alexandru Vasile v Vicentiu Andrei Niculescu | 4-6,6-1,6-1 |
| ITF Romania F11 | 2018/08/26 13:00 | Mihai Razvan Marinescu v Vicentiu Andrei Niculescu | 6-2,7-5 |
| ITF Romania F10 | 2018/08/20 07:00 | Imanol L Morillo v Vicentiu Andrei Niculescu | 3-6,6-3,6-0 |
| ITF Romania F9 | 2018/08/12 08:30 | Melnic, Vladislav v Vicentiu Andrei Niculescu | 6-4,6-3 |
| ITF Romania F8 | 2018/08/05 11:30 | Mircea-Alexandru Jecan v Vicentiu Andrei Niculescu | 6-2,6-1 |