2018/03/28 | Yangpyeong | | 2-1 Pro. | | Siheung Citizen | | | | |
| Ulsan Hyundai | | 1-3 Pro. | | Gyeongju KHNP | | | | |
| Asan Mugunghwa | | 7-0 | | Yeoju Citizen | | | | |
| Chuncheon | | 3-2 | | Jeonju | | | | |
| Cheonan | | 3-2 | | Jeonju University | | | | |
| Busan Kyotong | | 4-0 | | Chungju Citizen | | | | |
| Gangneung City | | 2-0 Pro. | | Pukyong National University | | | | |
| Ansan Greeners | | 7-0 | | Suwon University | | | | |
| Mokpo City | | 3-1 | | Jungnang Chorus | | | | |
| Daejeon Korail | | 3-1 | | Gwangju | | | | |
| Anyang | | 2-1 | | Changwong City | | | | |
| Gimhae City | | 0-0 (5-4 Pen.) | | Cheongju City | | | | |
| Seongnam FC | | 1-0 | | Daejeon Hana Citizen | | | | |
| Korea University | | 0-0 (1-3 Pen.) | | Seoul E-Land | | | | |
2018/03/31 | Hwaseong | | 2-3 | | Yong In University | | | | |
| Gimpo Citizen | | 2-1 | | Pyeongtaek Citizen | | | | |
| Pocheon | | 2-0 | | Incheon University | | | | |
| Paju Citizen | | 0-1 | | Gyeongju Citizen | | | | |
2018/04/04 | Busan IPark | | 2-1 | | Bucheon 1995 | | | | |