Shuko Aoyama crashed to a straight-sets defeat to American No. 8 seed Lauren Davis in the second round in singles competition at the Japan Women's Open on Thursday.
Davis took a little over an hour to thrash qualifier Aoyama 6-1, 6-1 and secure her place in the quarterfinals at Utsubo Tennis Center in Osaka.
Davis' opponent in the last eight will be third-seeded Ukrainian Elina Svitolina, who eliminated Naomi Osaka on Wednesday.
In other matches Thursday, defending champion and top seed Samantha Stosur defeated fellow Australian Jarmila Gajdosova, who retired in the second set with Stosur leading 7-6 (7-4), 1-0.
Fifth seed Zarina Diyas of Kazakhstan advanced with a 6-0, 6-1 defeat of Spain's Lara Arruabarrena.
Fourth seed Coco Vandeweghe of the United States was knocked out after suffering a 6-2, 3-6, 6-3 defeat to Croatia's Ana Konjuh.