Zarina Diyas Zarina Diyas (; ; born 18 October 1993) is a Kazakh professional tennis player. She has been WTA rankings, ranked as high as No. 31 by the Women's Tennis Association, WTA. Diyas has won one singles title on the WTA Tour, at the 2017 Japan Women' ...

was the defending champion, but lost in the quarterfinals to

Zhang Shuai Zhang Shuai ( zh , s = 张帅 , p = Zhāng Shuài ; ; born 21 January 1989) is a Chinese professional tennis player. She has a career-high doubles WTA rankings, ranking of world No. 2, achieved in July 2022 and a singles ranking of No. 22 re ...

Hsieh Su-wei Hsieh Su-wei (; ; born 4 January 1986) is a Taiwanese professional tennis player. A former List of WTA number 1 ranked doubles tennis players, world No. 1 in Doubles tennis, doubles with nine Grand Slam (tennis), Grand Slam titles, she is rega ...

won her first title in six years, beating

Amanda Anisimova Amanda Kay Victoria Anisimova ( ; ; born August 31, 2001) is an American professional tennis player. She has a career-high singles WTA rankings, WTA ranking of world No. 13, achieved on 16 June 2025. Anisimova has won three WTA Tour titles, inc ...

in the final 6–2, 6–2.

Seeds

Draw

Finals

Top half

Bottom half

Qualifying

Seeds

Qualifiers

Qualifying draw

First qualifier

Second qualifier

Third qualifier

Fourth qualifier

References

Main DrawQualifying Draw
{{DEFAULTSORT:2018 Japan Women's Open - Singles Japan Women's Open - Singles

2018 Singles Eighteen or 18 may refer to: * 18 (number) * One of the years 18 BC, AD 18, 1918, 2018 Film, television and entertainment * ''18'' (film), a 1993 Taiwanese experimental film based on the short story ''God's Dice'' * ''Eighteen'' (film), a 2 ...

2018 Japan Women's Open