Twenty-year-old Zhang shot a six-under 66 on Saturday to reach 11 under and take a two-shot lead going into the final round of the inaugural Mizuho Americans Open at Liberty National in New Jersey.
A day after shooting a 64, world No.5 Lee struggled to get her putter going and carded an even par 72 with just two birdies to be sole fifth, four shots behind Zhang.
Fellow Australian Steph Kyriacou had the best round of the day, shooting a 65 that included an eagle, six birdies and an early bogey to be six shots off the pace.
A two-time NCAA champion, Zhang won 12 of 20 events in her two college years at Stanford, with many viewing it as a sign of things to come.
She made six birdies in a bogey-free third round on a raw, overcast day to jump to the top of the leaderboard.
Cheyenne Knight, who was tied with Lee for the halfway lead, was tied for second with Atthaya Thitikul of Thailand and Aditi Ashok of India, who both shot 68s. Knight had a 69.
Lee was, a shot ahead of Jennifer Kupcho (69) rookie Hae Ran Ryu (66) and Eun-Hee Ji (70).
No.3 ranked Lydia Ko, who was a shot behind the lead entering the round, and No.8 ranked Brooke Henderson, who was two shots off the pace, finished at one-under. Ko shot 77, and Henderson 76.
