# 2018 Gimcheon Open ATP Challenger – Singles

Thomas Fabbiano was the defending champion but chose not to defend his title.
Yoshihito Nishioka won the title after defeating Vasek Pospisil 6–4, 7–5 in the final.

## Seeds

* Matthew Ebden (first round, retired)
* Vasek Pospisil (final)
* Jordan Thompson (second round)
* Dudi Sela (second round)
* Lu Yen-hsun (withdrew)
* Mackenzie McDonald (quarterfinals)
* Go Soeda (quarterfinals)
* Jason Jung (second round)

## Draw
### Key

* Q = Qualifier
* WC = Wild card
* LL = Lucky loser
* Alt = Alternate
* SE = Special exempt
* PR = Protected ranking
* ITF = ITF entry
* JE = Junior exempt
* w/o = Walkover
* r = Retired
* d = Defaulted
* SR = Special ranking

### Finals

| Semifinals | Semifinals | Semifinals | Semifinals | Final | Final | Final | Final |
| | Max Purcell | 4 | 0 | | | | |
| Q | Yoshihito Nishioka | 6 | 6 | | | | |
| Q | Yoshihito Nishioka | 6 | 6 | Q | Yoshihito Nishioka | 6 | 7 |
| | | | | 2 | Vasek Pospisil | 4 | 5 |
| | Kwon Soon-woo | 1 | 2 | 2 | Vasek Pospisil | 4 | 5 |
| 2 | Vasek Pospisil | 6 | 6 | | | | |

### Top half

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Second round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals |
| 1 | M Ebden | 7$^7$ | 1 | 0$^r$ | | | | | | | | | | | | | |
| | Z Li | 6$^5$ | 6 | 3 | | Z Li | 1 | 4 | | | | | | | | | |
| | B Schnur | 7$^8$ | 1 | 3 | | M Purcell | 6 | 6 | | | | | | | | | |
| | M Purcell | 6$^6$ | 6 | 6 | | | | | | | M Purcell | 6 | 6 | | | | |
| WC | U-s Park | 5 | 2 | | | | | | | 7 | G Soeda | 3 | 3 | | | | |
| | Y Takahashi | 7 | 6 | | | Y Takahashi | 6$^3$ | 2 | | | | | | | | | |
| | R Statham | 2 | 6 | 4 | 7 | G Soeda | 7$^7$ | 6 | | | | | | | | | |
| 7 | G Soeda | 6 | 3 | 6 | | | | | | | | | | | M Purcell | 4 | 0 |
| 3 | J Thompson | 6 | 6 | | | | | | | | | | | Q | Y Nishioka | 6 | 6 |
| WC | Y-s Chung | 4 | 1 | | 3 | J Thompson | 2 | 4 | | | | | | | | | |
| Q | Y Nishioka | 6 | 6 | | Q | Y Nishioka | 6 | 6 | | | | | | | | | |
| | J-P Smith | 4 | 0 | | | | | | | Q | Y Nishioka | 6 | 6 | | | | |
| WC | Lee Young-seok | 1 | 1 | | | | | | | Q | M Ochi | 2 | 2 | | | | |
| Q | Makoto Ochi | 6 | 6 | | Q | M Ochi | 4 | 6 | 7$^7$ | | | | | | | | |
| WC | D-h Lee | 7$^7$ | 2 | 3 | LL | L Saville | 6 | 1 | 6$^1$ | | | | | | | | |
| LL | L Saville | 6$^3$ | 6 | 6 | | | | | | | | | | | | | |

### Bottom half

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Second round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals |
| 6 | M McDonald | 7$^7$ | 7$^7$ | | | | | | | | | | | | | | |
| | Ze Zhang | 6$^4$ | 6$^5$ | | 6 | M McDonald | 4 | 6 | 6 | | | | | | | | |
| | F Peliwo | 6 | 6 | | | F Peliwo | 6 | 3 | 1 | | | | | | | | |
| | D Wu | 4 | 1 | | | | | | | 6 | M McDonald | 5 | 5 | | | | |
| | S-w Kwon | 6 | 2 | 6 | | | | | | | S-w Kwon | 7 | 7 | | | | |
| | D Kelly | 4 | 6 | 2 | | S-w Kwon | 4 | 6 | 6 | | | | | | | | |
| | M Banes | 3 | 2 | | 4 | D Sela | 6 | 3 | 1 | | | | | | | | |
| 4 | D Sela | 6 | 6 | | | | | | | | | | | | S-w Kwon | 1 | 2 |
| 8 | J Jung | 6 | 5 | 7$^7$ | | | | | | | | | | 2 | V Pospisil | 6 | 6 |
| | T Ito | 3 | 7 | 6$^4$ | 8 | J Jung | 6$^6$ | 0 | | | | | | | | | |
| Q | Renta Tokuda | 6 | 7 | | Q | R Tokuda | 7$^8$ | 6 | | | | | | | | | |
| Q | W Trongcharoenchaikul | 1 | 5 | | | | | | | Q | R Tokuda | 4 | 4 | | | | |
| | J Kubler | 6 | 6 | | | | | | | 2 | V Pospisil | 6 | 6 | | | | |
| | M Giron | 4 | 2 | | | J Kubler | 4 | 4 | | | | | | | | | |
| | Y Uchiyama | 7$^7$ | 2 | 2 | 2 | V Pospisil | 6 | 6 | | | | | | | | | |
| 2 | V Pospisil | 6$^5$ | 6 | 6 | | | | | | | | | | | | | |