At one stage in the last round she had to play a shot from under a tree with a bee-hive above her head but eventually focused and went on to win the tournament three strokes clear of second-placed Lewis.
"I was just scared of the bees and I didn't want to be stung," Kim said through a translator.
"So, I kept asking if I can get relief and I kept asking and they said, 'No, you can't.' So, I just swallowed my fears and tried to play the shot as best I could."
"I think the situation on hole 10 helped," Kim said.
"After I went through there and I got a bogey, I just realized there's no time to feel pressure or feel afraid. I just had to go out there and play," she added.
South Korean Lee Il-Hee grabbed a share of third place alongside Lee Mi-Hyang and Pornanong Phatlum with a six-under 66, while world No 1 Lydia Ko had her third straight 69 to tie for sixth at 15-under, to extender her run of breaking par to 27 tournaments worldwide.
-21 Hyo Joo Kim (Kor)
-18 Stacy Lewis (USA)
-16 Lee Il-Hee (KOR)
-16 Pornanong Phatlum (THA)
-16 Lee Mi-Hyang (KOR)
-15 Anna Nordqvist (SWE)
-15 Austin Ernst (USA)
-15 Kim Sei-Young (KOR)
-15 Choi Na-Yeon (KOR)
-15 Lydia Ko (NZL)