"I feel like even if I hit one semi-short ball she would come in and crush it, so I had to play really well", the 64th-ranked Osaka said of defeating the fifth-ranked Williams. Pavlyuchenkova overcame three double faults to win her match in 1 hour, 34 minutes.
"I feel like I made a few too many errors on my return game which ultimately led to a hard first set".
On Thursday, world No. 6 tennis player Caroline Wozniacki made a decision to drop out of the Hong Kong Tennis Open because of an elbow injury. "I felt like as the match went on I kept getting better and better".
A tearful third seed Wozniacki appeared on center court just after her second-round match against Lizette Cabrera had been due to start to announce she had injured her elbow in practice. "Unfortunately I have to withdraw from the tournament", Wozniacki said.
World No.4 Svitolina, who won the Toronto Masters title in August, was to have faced American Nicole Gibbs, who advanced without firing a shot.
Wozniacki, who beat Eugenie Bouchard 6-1, 6-1 in the opening round on Wednesday, and Svitolina have already booked their places in the season-ending WTA Finals in Singapore which take place from October 22nd to 29th.
British world No. 10 Johanna Konta also cancelled her trip because of a foot problem, while France's 13th-ranked Kristina Mladenovic opted out with a knee injury.
Japanese teenager Naomi Osaka fought back from an early break to stun Venus Williams in straight sets and move through to the Hong Kong Open quarter-finals yesterday. She was joined by Wang Qiang who defeated Thai Luksika Kumkhum 6-4 6-4.
Australian Samantha Stosur rebounded after dropping the first set to record a 3-6, 6-4, 6-0 victory over fourth-seeded Agnieszka Radwanska of Poland.