# 2018 OEC Kaohsiung – Singles

Evgeny Donskoy was the defending champion but chose not to defend his title.
Gaël Monfils won the title after defeating Kwon Soon-woo 6–4, 2–6, 6–1 in the final.

## Seeds

* Gaël Monfils (champion)
* Malek Jaziri (semifinals)
* Jason Kubler (first round)
* Jason Jung (second round)
* Lloyd Harris (second round)
* Ramkumar Ramanathan (second round)
* Ernests Gulbis (quarterfinals)
* Prajnesh Gunneswaran (first 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 | Final |
| 1/WC | Gaël Monfils | 6 | 6 | | | | | |
| | Lee Duck-hee | 1 | 1 | | | | | |
| | Lee Duck-hee | 1 | 1 | 1/WC | Gaël Monfils | 6 | 2 | 6 |
| | | | | Q | Kwon Soon-woo | 4 | 6 | 1 |
| Q | Kwon Soon-woo | 6 | 6 | Q | Kwon Soon-woo | 4 | 6 | 1 |
| 2 | Malek Jaziri | 3 | 4 | | | | | |

### 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/WC | G Monfils | 5 | 6 | 6 | | | | | | | | | | | | | |
| Q | A Santillan | 7 | 3 | 4 | 1/WC | G Monfils | 6 | 6 | | | | | | | | | |
| | G Soeda | 7$^7$ | 7$^7$ | | | G Soeda | 2 | 3 | | | | | | | | | |
| LL | Y Sugita | 6$^4$ | 6$^4$ | | | | | | | 1/WC | G Monfils | 7$^7$ | 6 | | | | |
| | Y Uchiyama | 7 | 6 | | | | | | | 7/WC | E Gulbis | 6$^4$ | 2 | | | | |
| SE | B Kavčič | 5 | 2 | | | Y Uchiyama | 2 | 4 | | | | | | | | | |
| | A Bublik | 1$^r$ | | | 7/WC | E Gulbis | 6 | 6 | | | | | | | | | |
| 7/WC | E Gulbis | 3 | | | | | | | | | | | | 1/WC | G Monfils | 6 | 6 |
| 4 | J Jung | 6 | 6 | | | | | | | | | | | | D-h Lee | 1 | 1 |
| Q | Y-s Chung | 3 | 4 | | 4 | J Jung | 6$^5$ | 4 | | | | | | | | | |
| | T Brkić | 2 | 6$^5$ | | | D-h Lee | 7$^7$ | 6 | | | | | | | | | |
| | D-h Lee | 6 | 7$^7$ | | | | | | | | D-h Lee | 6 | 7 | | | | |
| | Y Nishioka | 3 | 0 | | | | | | | Q | F Ferreira Silva | 2 | 5 | | | | |
| Q | F Ferreira Silva | 6 | 6 | | Q | F Ferreira Silva | 3 | 6 | 7$^7$ | | | | | | | | |
| | M Neuchrist | 4 | 2 | | 6 | R Ramanathan | 6 | 4 | 6$^4$ | | | | | | | | |
| 6 | R Ramanathan | 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 | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals |
| 5 | L Harris | 6$^5$ | 6 | 6 | | | | | | | | | | | | | | |
| | J Ward | 7$^7$ | 3 | 2 | 5 | L Harris | 3 | 5 | | | | | | | | | | |
| WC | T-l Wu | 3 | 2 | | Q | S-w Kwon | 6 | 7 | | | | | | | | | | |
| Q | S-w Kwon | 6 | 6 | | | | | | | Q | S-w Kwon | 6 | 6 | | | | | |
| | H Moriya | 4 | 3 | | | | | | | | B Schnur | 3 | 4 | | | | | |
| | T-h Yang | 6 | 6 | | | T-h Yang | 5 | 3 | | | | | | | | | | |
| | B Schnur | 6 | 7$^7$ | | | B Schnur | 7 | 6 | | | | | | | | | | |
| 3 | J Kubler | 4 | 6$^4$ | | | | | | | | | | | | Q | S-w Kwon | 6 | 6 |
| 8 | P Gunneswaran | 3 | 7 | 3 | | | | | | | | | | | 2 | M Jaziri | 3 | 4 |
| | J Rodionov | 6 | 5 | 6 | | J Rodionov | 6 | 1 | 6 | | | | | | | | | |
| | M Purcell | 7$^7$ | 5 | 3 | WC | C-h Tseng | 4 | 6 | 3 | | | | | | | | | |
| WC | C-h Tseng | 6$^4$ | 7 | 6 | | | | | | | J Rodionov | 4 | 7$^8$ | 4 | | | | |
| | F Peliwo | 3 | 0 | | | | | | | 2 | M Jaziri | 6 | 6$^6$ | 6 | | | | |
| | F Gaio | 6 | 6 | | | F Gaio | 3 | 6$^4$ | | | | | | | | | | |
| SE | Z Li | 2 | 2 | | 2 | M Jaziri | 6 | 7$^7$ | | | | | | | | | | |
| 2 | M Jaziri | 6 | 6 | | | | | | | | | | | | | | | |