Breaks in the fifth game of both sets proved decisive as Zhang closed out a 6-4, 6-4 victory in an hour and 18 minutes.
Honolulu is the final event of a memorable year for Zhang that has seen her emerge as an unlikely standard bearer for Chinese tennis. Little more than 12 months ago, Zhang was contemplating retirement on the back of a dispiriting spell on tour. Sam Stosur talked her out of it and she has been on an upward trajectory ever since.
In January she ended her long-running Grand Slam hoodoo by making it all the way through qualifying and into the quarterfinals of the Australian Open, building on this platform with credible showings in Tokyo, Seoul, Beijing and Zhuhai to leave herself on the verge of the Top 20.
Meeting her for a place in the final will be No.6 seed Evgeniya Rodina, who posted a battling win over Sachia Vickery. Rodina, who won last week's OEC Taipei WTA Challenger, was forced to dig deep against Vickery prevailing in a tense finale to triumph, 6-3, 3-6, 6-4, in a fraction under two hours.
Another player on the up is CiCi Bellis, who confidently booked her final four spot by swatting aside Sara Sorribes Tormo, 6-1, 6-1.
Bellis recently broke into the Top 100 for the first time after back-to-back titles on the ITF Circuit, and broke serve six times against Sorribes Tormo to extend her winning sequence to 12 matches. Next she faces Jacqueline Cako, who advanced when Sabine Lisicki retired with a shoulder injury.