Stadium: Centre Court Round: 46 Ground: Clay
| Challenger Budapest Qual | 2018/02/03 08:30 | Karimov, Jurabek v Sieber, Marc | 1-6,3-6 |
| ITF Turkey F3 | 2018/01/26 09:30 | Dimitar Kuzmanov v Sieber, Marc | 2-6,7-5,7-5 |
| ITF Turkey F3 | 2018/01/25 10:00 | Kiyamov, Timur v Sieber, Marc | 6-4,1-6,3-6 |
| ITF Turkey F3 | 2018/01/23 09:55 | Mubarak Shannan Zayid v Sieber, Marc | 6-7,1-6 |
| ITF Turkey F2 | 2018/01/20 07:30 | Dimitar Kuzmanov v Sieber, Marc | 6-1,4-6,7-5 |
| ITF Turkey F2 | 2018/01/19 08:40 | Sieber, Marc v Quinzi, Gianluigi | 7-5,6-4 |
| ITF Turkey F2 | 2018/01/18 10:05 | Sieber, Marc v Nik Razborsek | 6-3,6-3 |
| ITF Turkey F2 | 2018/01/17 09:45 | Sieber, Marc v Glasspool, Lloyd | 6-2,6-0 |
| Challenger Budapest Qual | 2018/02/03 08:30 | Antoine Escoffier v Bega, Alessandro | 3-6,5-7 |
| ITF France F3 | 2018/01/28 14:00 | Bega, Alessandro v Vand Der Duim, Antal | 4-6,6-4,7-6 |
| ITF France F3 | 2018/01/27 12:55 | Albano Olivetti v Bega, Alessandro | 4-6,2-6 |
| ITF France F3 | 2018/01/26 11:00 | Bega, Alessandro v Crepatte, Baptiste | 6-1,6-0 |
| ITF France F3 | 2018/01/25 11:00 | Bega, Alessandro v Voljacques, Hugo | 7-6,6-0 |
| ITF France F3 | 2018/01/23 13:20 | Bega, Alessandro v Marc-Andrea Huesler | 2-6,6-3,7-5 |
| Challenger Koblenz Qual | 2018/01/15 18:10 | Heyman, Christopher v Bega, Alessandro | 6-1,6-4 |
| Challenger Koblenz Qual | 2018/01/15 14:05 | Farquharson, Tom v Bega, Alessandro | 6-7,5-7 |