With her first victory of 2018, Henderson has now won a tournament in each of her four seasons on the LPGA Tour.
The Canadian followed her opening 68 with a superb six-under-par 66 today to reach 10 under, two clear of American Mo Martin and Chinese world No.1 Shanshan Feng with another two shots back to the rest of the field, including Sweden's recent ANA Inspiration victor Pernilla Lindberg. Hataoka shot a four-under 68 while Park carded a one-under 71.
"The wind wasn't as strong early today and there were softer conditions", said Henderson. She was two shots back after her fifth birdie of the day, at the 14th, but parred in.
World No 1 Shanshan Feng finished five strokes back in a share of third alongside Ariya Jutanugarn and Inbee Park, who finished her level-par 72 with back-to-back bogeys.
Henderson of Canada won with 12 under par.
"They're in my thoughts and prayers", she said.First-round leader Feng rolled in three birdies in her bogey free round, while defending champion Cristie Kerr had a 75 to reach two-over 146, six shots back of Henderson.
Spain's Azahara Munoz had a 67, the low round of the day, to finish second. "Watching Pernilla [Lindberg] win a major was a lot of motivation".
A stroke ahead entering the round after late putting trouble in a third-round 73, Henderson finished at 12-under 276. Edberg, from Sweden, is ranked 850th in her first LPGA start.
Ji Eun-hee was the second-best finisher among Korean golfers at the Lotte Championships, finishing tied for 11th at 3 under par along with KLPGA Tour golfer Kim Ji-hyun who played under invitation. She played the first 11 holes Saturday in 2 under to carve out a three-shot advantage, then faltered again.
Starting Thursday, the LPGA Tour will continue at the inaugural Hugel-JTBC LA Open in California.