# 2018 Japan Women's Open – Singles

Zarina Diyas was the defending champion, but lost in the quarterfinals to Zhang Shuai.
Hsieh Su-wei won her first title in six years, beating Amanda Anisimova in the final 6–2, 6–2.

## Seeds

* Zhang Shuai (semifinals)
* Hsieh Su-wei (champion)
* Yulia Putintseva (first round, retired)
* Wang Qiang (semifinals)
* Ajla Tomljanović (quarterfinals)
* Zarina Diyas (quarterfinals)
* Zheng Saisai (second round)
* Magda Linette (quarterfinals)

## 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 |
| 1 | Zhang Shuai | 6$^4$ | 5 | | | | |
| Q | Amanda Anisimova | 7$^7$ | 7 | | | | |
| Q | Amanda Anisimova | 7$^7$ | 7 | Q | Amanda Anisimova | 2 | 2 |
| | | | | 2 | Hsieh Su-wei | 6 | 6 |
| 4 | Wang Qiang | 4 | 4 | 2 | Hsieh Su-wei | 6 | 6 |
| 2 | Hsieh Su-wei | 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 | S Zhang | 7 | 6 | | | | | | | | | | | | | | |
| | M Fręch | 5 | 3 | | 1 | S Zhang | 6 | 7$^7$ | | | | | | | | | |
| WC | N Hibino | 6 | 6 | | WC | N Hibino | 4 | 6$^4$ | | | | | | | | | |
| | E Bouchard | 4 | 4 | | | | | | | 1 | S Zhang | 6 | 7 | | | | |
| | K Kozlova | 6 | 6 | | | | | | | 6 | Z Diyas | 4 | 5 | | | | |
| Q | Y Zhang | 2 | 3 | | | K Kozlova | 7$^7$ | 2 | 5 | | | | | | | | |
| | S Sorribes Tormo | 2 | 1 | | 6 | Z Diyas | 6$^3$ | 6 | 7 | | | | | | | | |
| 6 | Z Diyas | 6 | 6 | | | | | | | | | | | 1 | S Zhang | 6$^4$ | 5 |
| 3 | Y Putintseva | 2 | 0$^r$ | | | | | | | | | | | Q | A Anisimova | 7$^7$ | 7 |
| | AK Schmiedlová | 6 | 0 | | | AK Schmiedlová | 5 | 7 | 6 | | | | | | | | |
| | V Golubic | 0 | 6 | 7$^7$ | | V Golubic | 7 | 5 | 3 | | | | | | | | |
| WC | M Doi | 6 | 3 | 6$^1$ | | | | | | | AK Schmiedlová | 3 | 1 | | | | |
| | J Fett | 1 | 1 | | | | | | | Q | A Anisimova | 6 | 6 | | | | |
| Q | A Anisimova | 6 | 6 | | Q | A Anisimova | 6 | 6 | | | | | | | | | |
| | A Riske | 5 | 4 | | 7 | S Zheng | 1 | 1 | | | | | | | | | |
| 7 | S Zheng | 7 | 6 | | | | | | | | | | | | | | |

### Bottom half

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals |
| 8 | M Linette | 6 | 6 | | | | | | | | | | | | | | |
| | J Larsson | 4 | 1 | | 8 | M Linette | 6 | 7$^7$ | | | | | | | | | |
| | T Zidanšek | 6 | 6 | | | T Zidanšek | 3 | 6$^3$ | | | | | | | | | |
| Q | Ar Rodionova | 2 | 4 | | | | | | 8 | M Linette | 2 | 2 | | | | | |
| | Y Duan | 7 | 2 | 2 | | | | | 4 | Q Wang | 6 | 6 | | | | | |
| | L Kumkhum | 5 | 6 | 6 | | L Kumkhum | 5 | 3 | | | | | | | | | |
| Q | P Hon | 6 | 1 | 3 | 4 | Q Wang | 7 | 6 | | | | | | | | | |
| 4 | Q Wang | 3 | 6 | 6 | | | | | | | | | | 4 | Q Wang | 4 | 4 |
| 5 | A Tomljanović | 6 | 6 | | | | | | | | | | | 2 | S-w Hsieh | 6 | 6 |
| | F Ferro | 4 | 1 | | 5 | A Tomljanović | 7 | 6 | | | | | | | | | |
| WC | M Kato | 6$^3$ | 2 | | | L Zhu | 5 | 4 | | | | | | | | | |
| | L Zhu | 7$^7$ | 6 | | | | | | 5 | A Tomljanović | 6 | 2 | 0 | | | | |
| PR | M Minella | 6 | 6 | | | | | | 2 | S-w Hsieh | 4 | 6 | 6 | | | | |
| | K Nara | 3 | 4 | | PR | M Minella | 3 | 2 | | | | | | | | | |
| | P Hercog | 6 | 1 | 3 | 2 | S-w Hsieh | 6 | 6 | | | | | | | | | |
| 2 | S-w Hsieh | 4 | 6 | 6 | | | | | | | | | | | | | |

## Qualifying
### Seeds

* Amanda Anisimova (qualified)
* Antonia Lottner (first round)
* Arina Rodionova (qualified)
* Han Xinyun (second round)
* Harriet Dart (second round)
* Danka Kovinić (first round)
* Priscilla Hon (qualified)
* Jang Su-jeong (qualifying competition)

### Qualifiers

* Amanda Anisimova
* Zhang Yuxuan
* Arina Rodionova
* Priscilla Hon

### Qualifying draw
#### First qualifier

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Second round | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition |
| 1 | Amanda Anisimova | 6 | 6 | | | | | | | | | | |
| | Momoko Kobori | 3 | 3 | | | | | | | | | | |
| | Momoko Kobori | 3 | 3 | | 1 | Amanda Anisimova | 6 | 3 | 6 | | | | |
| | | | | | WC | Urszula Radwańska | 1 | 6 | 4 | | | | |
| WC | Urszula Radwańska | 7$^9$ | 6 | | WC | Urszula Radwańska | 1 | 6 | 4 | | | | |
| | Miharu Imanishi | 6$^7$ | 1 | | | | | | | | | | |
| | Miharu Imanishi | 6$^7$ | 1 | | | | | | | 1 | Amanda Anisimova | 6 | 6 |
| | | | | | | | | | | Alt | Hiroko Kuwata | 3 | 2 |
| Alt | Hiroko Kuwata | 6 | 6$^3$ | 6 | | | | | | | | | | Alt | Hiroko Kuwata | 3 | 2 |
| | Mai Minokoshi | 1 | 7$^7$ | 3 | | | | | | | | | |
| | Mai Minokoshi | 1 | 7$^7$ | 3 | Alt | Hiroko Kuwata | 6 | 7 | | | | | |
| | | | | | 5 | Harriet Dart | 4 | 5 | | | | | |
| WC | Makoto Ninomiya | 2 | 7$^7$ | 2 | 5 | Harriet Dart | 4 | 5 | | | | | |
| 5 | Harriet Dart | 6 | 6$^5$ | 6 | | | | | | | | | |

#### Second qualifier

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition |
| 2 | Antonia Lottner | 3 | 4 | | | | | | | | | | |
| | Zhang Yuxuan | 6 | 6 | | | | | | | | | | |
| | Zhang Yuxuan | 6 | 6 | | | Zhang Yuxuan | 6 | 7 | | | | | |
| | | | | | | Valeria Savinykh | 3 | 5 | | | | | |
| | Zhang Kailin | 3 | 7 | 4 | | Valeria Savinykh | 3 | 5 | | | | | |
| | Valeria Savinykh | 6 | 5 | 6 | | | | | | | | | |
| | Valeria Savinykh | 6 | 5 | 6 | | | | | | Zhang Yuxuan | 4 | 6 | 6 |
| | | | | | | | | | 8 | Jang Su-jeong | 6 | 3 | 1 |
| | Junri Namigata | 2 | 3 | | | | | | | | | | | 8 | Jang Su-jeong | 6 | 3 | 1 |
| | Danielle Lao | 6 | 6 | | | | | | | | | | |
| | Danielle Lao | 6 | 6 | | | Danielle Lao | 5 | 3 | | | | | |
| | | | | | 8 | Jang Su-jeong | 7 | 6 | | | | | |
| | Ellen Perez | 6 | 3 | 3 | 8 | Jang Su-jeong | 7 | 6 | | | | | |
| 8 | Jang Su-jeong | 3 | 6 | 6 | | | | | | | | | |

#### Third qualifier

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Second round | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition |
| 3 | Arina Rodionova | 6 | 0 | | | | | | | | | | | |
| | Eri Hozumi | 0 | 0$^r$ | | | | | | | | | | | |
| | Eri Hozumi | 0 | 0$^r$ | | 3 | Arina Rodionova | 3 | 6 | 7 | | | | | |
| | | | | | WC | Chihiro Muramatsu | 6 | 4 | 5 | | | | | |
| | Risa Ozaki | 4 | 6 | 3 | WC | Chihiro Muramatsu | 6 | 4 | 5 | | | | | |
| WC | Chihiro Muramatsu | 6 | 3 | 6 | | | | | | | | | | |
| WC | Chihiro Muramatsu | 6 | 3 | 6 | | | | | | 3 | Arina Rodionova | 3 | 6 | 6 |
| | | | | | | | | | | | Sílvia Soler Espinosa | 6 | 2 | 3 |
| | Anna Zaja | 6 | 6 | | | | | | | | | | | | Sílvia Soler Espinosa | 6 | 2 | 3 |
| | Dejana Radanović | 4 | 3 | | | | | | | | | | | |
| | Dejana Radanović | 4 | 3 | | | Anna Zaja | 3 | 4 | | | | | | |
| | | | | | | Sílvia Soler Espinosa | 6 | 6 | | | | | | |
| | Sílvia Soler Espinosa | 6 | 7 | | | Sílvia Soler Espinosa | 6 | 6 | | | | | | |
| 6 | Danka Kovinić | 4 | 5 | | | | | | | | | | | |

#### Fourth qualifier

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition |
| 4 | Han Xinyun | 6 | 6 | | | | | | | | | |
| WC | Shuko Aoyama | 4 | 1 | | | | | | | | | |
| WC | Shuko Aoyama | 4 | 1 | | 4 | Han Xinyun | 6$^7$ | 5 | | | | |
| | | | | | | Varvara Flink | 7$^9$ | 7 | | | | |
| | Jaimee Fourlis | 5 | 2 | | | Varvara Flink | 7$^9$ | 7 | | | | |
| | Varvara Flink | 7 | 6 | | | | | | | | | |
| | Varvara Flink | 7 | 6 | | | | | | | Varvara Flink | 3 | 2 |
| | | | | | | | | | 7 | Priscilla Hon | 6 | 6 |
| | Liang En-shuo | 6 | 5 | 4 | | | | | | | | | 7 | Priscilla Hon | 6 | 6 |
| | Han Na-lae | 3 | 7 | 6 | | | | | | | | |
| | Han Na-lae | 3 | 7 | 6 | | Han Na-lae | 2 | 2 | | | | |
| | | | | | 7 | Priscilla Hon | 6 | 6 | | | | |
| | Deniz Khazaniuk | 3 | 6$^5$ | | 7 | Priscilla Hon | 6 | 6 | | | | |
| 7 | Priscilla Hon | 6 | 7$^7$ | | | | | | | | | |