stadio: Court 4 Round: 45 Ground: Clay
| Challenger Shymkent - Qual. | 2018/06/04 05:00 | Jurij Rodionov v Nikola Cacic | 7-6,6-7,7-6 |
| Challenger Shymkent - Qual. | 2018/06/03 05:50 | Nikola Cacic v Joao Menezes | 6-4,7-6 |
| Challenger Shymkent - Qual. | 2018/06/02 05:30 | Nikola Cacic v Marko Djokovic | 7-5,6-4 |
| Challenger Samarcanda - Qual. | 2018/05/13 05:00 | Roman Safiullin v Nikola Cacic | 6-3,7-5 |
| Challenger Samarcanda - Qual. | 2018/05/12 06:15 | Nikola Cacic v Denis Matsukevich | 7-5,7-6 |
| Challenger Karshi - Qual. | 2018/05/07 05:30 | Tristan Lamasine v Nikola Cacic | 6-4,6-1 |
| Challenger Karshi - Qual. | 2018/05/06 07:50 | Olimjon Nabiev v Nikola Cacic | 3-6,2-6 |
| Challenger Karshi - Qual. | 2018/05/05 10:00 | Alexander Pavlioutchenkov v Nikola Cacic | 6-7,2-6 |
| Challenger Shymkent - Qual. | 2018/06/03 05:55 | Mukund Sasikumar v Renta Tokuda | 4-6,6-1,7-5 |
| Challenger Busan - Qual. | 2018/05/13 02:00 | Luke Saville v Renta Tokuda | 6-2,2-6,6-1 |
| Challenger Busan - Qual. | 2018/05/12 02:35 | Jacob Grills v Renta Tokuda | 7-6,5-7,3-6 |
| Challenger Gimcheon | 2018/05/11 03:15 | Renta Tokuda v Vasek Pospisil | 4-6,4-6 |
| Challenger Gimcheon | 2018/05/10 03:40 | Jason Jung v Renta Tokuda | 6-7,0-6 |
| Challenger Gimcheon | 2018/05/08 05:00 | Renta Tokuda v Wishaya Trongcharoenchaikul | 6-1,7-5 |
| Challenger Gimcheon - Qual. | 2018/05/07 05:00 | Renta Tokuda v Brydan Klein | 1-6,6-3,6-4 |
| Challenger Gimcheon - Qual. | 2018/05/06 04:30 | Renta Tokuda v Young Seok Kim | 6-3,6-2 |