Naomi Osaka booked her ticket to the Toray Pan Pacific Open semifinals with a straight-sets win against Barbora Strycova of the Czech Republic on Friday.
Having quickly overpowered Slovakia's Dominika Cibulkova in the previous round, the U.S. Open champion had to dig deeper for her 6-3, 6-4 victory over the 25th-ranked Strycova in 1 hour, 31 minutes.
Osaka, the world No. 7 struggled to land her first serve early in each set at Arena Tachikawa Tachihi and gave her opponent a number of second chances with inaccurate shots. But in both sets, the local favorite eventually took control after finding her rhythm.