The event this year has been promoted to WTA 125K series level.
Zhang battled Chinese qualifier Han Xinyun for more than 2 hours before finishing off a 6-2, 7-6 (7-3) win. She had five breaks, needing two to hold off Han and force the second-set tiebreaker.
A pair of Thai players advanced to the second round with seventh-seeded Tamarine Tanasugarn getting past Junri Namigata 6-1 4-6, 6-3 and Noppawan Lertcheewakarn racing by Chen Chin-Wei 6-1, 6-2.
Tanasugarn finished with six breaks and took more than half the points off Namigata's serve. Lertcheewakarn dropped 11 points over eight games serving and didn't face a break point.
Also Monday, Zarina Diyas took out Zhang Ling 6-2, 3-6, 6-2 and Lee So-ra advanced when Yang Zi retired in the second set. Lee was ahead 7-6 (7-3), 3-0 when the match was stopped.