Stadium: Court 5 Round: 46 Ground: Clay
| Challenger Sibiu Qual | 2018/09/15 10:00 | Grigoriu, Patrick v Frunza, Nicolae | 3-6,4-6 |
| ITF Romania F13 | 2018/09/13 06:30 | Lucas Gerch v Frunza, Nicolae | 3-6,7-5,6-2 |
| ITF Romania F13 | 2018/09/12 06:00 | Stoica, Vlad v Frunza, Nicolae | 0-6,5-7 |
| ITF Romania F12 | 2018/09/07 10:10 | Gabi Adrian Boitan v Frunza, Nicolae | 0-6,1-6 |
| ITF Romania F12 | 2018/09/06 07:00 | Lucas Gerch v Frunza, Nicolae | 4-6,4-6 |
| ITF Romania F11 | 2018/08/30 11:50 | Fortuna, Claudio v Frunza, Nicolae | 5-7,3-6 |
| ITF Romania F11 | 2018/08/29 09:45 | Ghilea, Vasile-Alexandru v Frunza, Nicolae | 2-6,3-6 |
| ITF Romania F10 | 2018/08/22 08:25 | Frunza, Nicolae v Lazarov, Alexandar | 2-6,3-6 |
| Challenger Seville | 2018/09/01 16:00 | Sieber, Marc v Bernabe Zapata Miralles | 6-7,3-6 |
| Challenger Mallorca | 2018/08/26 11:30 | Federico Zeballos v Sieber, Marc | 3-6,6-1,6-3 |
| Challenger Meerbusch | 2018/08/14 12:30 | Sieber, Marc v Tatlot, Johan Sebastien | 6-7,6-4,4-6 |
| Meerbusch, Allemagne, Qualifications | 2018/08/13 09:00 | Tristan Lamasine v Sieber, Marc | 6-7,5-7 |
| Meerbusch, Allemagne, Qualifications | 2018/08/12 09:40 | Sieber, Marc v Adrian Oetzbach | 6-0,6-0 |
| Meerbusch, Allemagne, Qualifications | 2018/08/11 11:45 | Mats Rosenkranz v Sieber, Marc | 3-6,3-6 |
| Challenger Pullach Qual | 2018/08/04 09:00 | Sieber, Marc v Lenz, Julian | 4-6,6-4,4-6 |
| Challenger Liberec Qual | 2018/07/29 08:30 | Sieber, Marc v Marvin Moeller | 2-6,5-7 |