Okamura, ranked 271st, lost in qualifying but was sent to the main draw as a lucky loser, but the 28-year-old defeated him 6-1 6-2.
Following her most successful season, Boulter is currently ranked 33rd in the world, and the distance between the two was evident.
Boulter was more consistent than Okamura, had more power from the back of the court, and displayed glimmers of skill.
“I feel like I am trying to get through these matches and playing some good tennis,” Boulter said.
Boulter wants to wrap up a season in which she has taken home two WTA trophies in style.
Boulter remarked, “I think I’m playing some good tennis and trying to get through these matches.”
Boulter, who has advanced to her first quarterfinal since Eastbourne in June, is hoping to cap off a season in which she has won two WTA titles with a bang.
