Seeking her first win on the U.S. circuit, the 23-year-old mixed three birdies with a lone bogey to post an 11-under total of 202.
Fellow Korean Q Baek, who clinched her maiden LPGA title at last year's LPGA KEB HanaBank Championship, was alone in second after a birdie at the par-five last earned her a 68.
South Korean world number one Park In-bee also birdied the 18th for a 67 to share third place at nine under with compatriot Chella Choi (65), second-ranked Lydia Ko of New Zealand (67), China's Shanshan Feng (68) and American Austin Ernst (66).
Jang, ranked 22nd in the world and a six-times winner on the Korean LPGA Tour, was well aware of the quality of the chasing pack but planned to focus on her own game in Sunday's final round.
"I think tomorrow my target is 15-under, so four more birdies is great, yeah," smiled Jang. "I don't think about (any other) player, just myself ... confidence and concentration and play. So tomorrow just one target: 15 under."
Jang's closest pursuer, Baek, will hope to draw on the experience of her breakthrough LPGA victory where she beat top-notch opponents American Brittany Lincicome and fellow Korean Chun In-gee in a playoff.
Lincicome went on to claim the first major of this season, the ANA Inspiration in April, while Chun clinched the third, last week's U.S. Women's Open in Lancaster, Pennsylvania.
"I learned a lot from the playoff I played against Lincicome and Gee Chun last year," said Baek, who carded three birdies in a bogey-free 68.
"I haven't made it to the next level yet, so hopefully that (playoff win) will give me good confidence going into tomorrow. Hopefully I step up to the next level."
Ko, who won last year's Marathon Classic, was disappointed after failing to birdie either of the closing par-fives -- the 17th and 18th -- but was happy with her position heading into Sunday's final round.
"I think I was a couple shots behind last year too so I don't mind the position I'm in right now," said Ko said. "It's great to return to a course where you've played well."
(Reporting by Mark Lamport-Stokes in Los Angeles; Editing by Gene Cherry/Peter Rutherford)
Share
