Pak's fellow Korean, Sun Young Yoo carded a Sunday 70 to take second place at two-under-par 214 on the Cleveland Heights Golf Course.
Second-round leader Aimee Cho struggled to a final-round, 5-over 77. She was joined in a tie for third place by Sasha Medina and Seon-Hwa Lee at even-par 216.
The win for Pak came in her first start on the Futures Tour.
Courtney Trimble, Tara Bateman, Alena Sharp, Allison Hanna, Ashley Prange, Lori Atsedes and Chiharu Yamaguchi shared sixth place at 1-over-par 217.