Fourth day of play was the last day at the Toray Pan Pacific Open for 3 seeded players

Sloane Stephens and Camila Giorgi opened the fourth day on the Osaka courts. Stephens and Giorgi had a H2H record of 2-2 before the match, so this match decided which player would lead in this statistics. Despite the fact that Stephens is third-seeded at the tournament, Giorgi did not give her a chance and won comfortably 6-0 and 6-3. Stephens has already added 3rd loss in a row to her account.

In the second match, the 36th woman in the WTA ranking Putintseva and qualifier Flink met. Putintseva defeated Flink three years ago at a Washington tournament and improved her record now in Osaka. She won 6-1 and 6-1 and in the quarterfinal she will face the home player Naomi Osaka.

Another surprise was the finalist of the Hiroshima tournament Misaki Doi, who managed to deal with Donna Vekic, the seventh seeded, in two sets. Vekic was leading 5-3 in the first set and had 2 set balls, but Doi was able to turn it and win the whole match.

Also Kiki Bertens added the third loss in a row after Sloane Stephens. In the second round she did not manage to outplay Anastasia Pavlyuchenkova, who defeated her 6-1 and 7-5.