Jang, who claimed her maiden title at the Coates Golf Championship last month, closed out the tournament with an eagle to finish 19 under through 72 holes.
Jang shot to the top of the leaderboard after shooting four birdies and an eagle on the par-five seventh, before Lee joined her at the top.
Jang Ha Na of South Korea plays a shot on the 6th hole during the third round of the HSBC Women's Champions Golf tournament on Saturday, March 5, 2016, in Singapore.
Defending champion and world number two Park In-bee had a day to forget, however, after she started her round with three bogeys in four holes but recovered slightly to sign for a one-over-par 73 that left her five off the pace in a tie for 20th.
Ariya Jutanugarn, Brooke Henderson, Stacy Lewis and Suzann Petterson are in a group of six players four shots off the lead but they will most likely need to shoot in the low 60s on Sunday if they are to overhaul the supremely consistent Jang.
"I was very comfortable on the front nine", Jang said.
Jang said she had been thinking about copying some of Beyonce's moves after watching her perform at the Super Bowl and winning her second title seemed like the ideal time to break it out.
"I may try and be a little more aggressive tomorrow", Jang said in a post-round interview.
She said her target was to win two tournaments this year and was surprised she accomplished it so early. "I'm trying to dance after my [final] putt". "I targeted two wins in 2016 but right now I did it and I'll change my targets to two more wins". "The wind was coming from a different direction so it made the course play a little bit tougher". It was her putter that made the difference, sinking a 30-footer on the 13th and 50-foot bomb on No. 14. Lee had a great round going as well but a few hiccups on the back nine dropped her down to a tie for third.
Leading by a single stroke overnight, she immediately extended her advantage to two shots when she rolled in a 12-foot birdie putt on the opening hole on Sunday, offering a taste of what was to come.
"Pornanong is my good friend, but I didn't think about her at every hole".
Two more birdies gave her a three-shot lead over Pornanong at the turn as the chasing pack faltered but the Korean gave the 26-year-old Thai a glimmer of hope with a messy bogey on the 11th that could have been a lot worse.
"I'm not afraid of the other players I just play my own game and make sure I enjoy my life every day, every week".
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