Stadium: Campo 4 Round: 45 Ground: Clay
| Challenger Recanati Qual | 2018/06/30 17:25 | Zhizhen Zhang v Cacic, Nikola | 6-7,6-3,6-4 |
| Challenger Almaty Qual | 2018/06/09 05:35 | Cacic, Nikola v Renta Tokuda | 6-7,4-6 |
| Shymkent, Kazakhstan, Qualifying | 2018/06/04 05:00 | Jurij Rodionov v Cacic, Nikola | 7-6,6-7,7-6 |
| Shymkent, Kazakhstan, Qualifying | 2018/06/03 05:50 | Cacic, Nikola v Joao Menezes | 6-4,7-6 |
| Shymkent, Kazakhstan, Qualifying | 2018/06/02 05:30 | Cacic, Nikola v Djokovic, Marko | 7-5,6-4 |
| Challenger Samarkand Qual | 2018/05/13 05:00 | Roman Safiullin v Cacic, Nikola | 6-3,7-5 |
| Challenger Samarkand Qual | 2018/05/12 06:15 | Cacic, Nikola v Matsukevitch, Denis | 7-5,7-6 |
| Challenger Karshi Qual | 2018/05/07 05:30 | Tristan Lamasine v Cacic, Nikola | 6-4,6-1 |