TOKYO (AP) Monica Puig rallied to upset 2013 champion Petra Kvitova 1-6, 6-4, 6-4 to reach the Pan Pacific Open quarterfinals on Wednesday.
The Puerto Rican, who also beat Kvitova on her way to becoming the Rio de Janeiro Olympic champion, recovered from 4-2 down in the final set. She saved 10 of 13 break points.
''It was difficult conditions today,'' Puig said. ''The conditions were heavy and the roof was open this time so it took me a little bit of time to adjust.''
Puig has yet to lose to a left-hander in 2016, and will next meet either defending champion Agnieszka Radwanska or Barbora Strycova.
Also, Japanese wild card Naomi Osaka beat sixth-seeded Dominika Cibulkova of Slovakia 6-2, 6-1 to set up a quarterfinal with either Karolina Pliskova or Aliaksandra Sasnovich.