American Danielle Kang overcame flailing nerves to fire a three-under-par 69 in the final round and claim the inaugural LPGA Shanghai title by two-strokes on Sunday.
Ariya Jutanugarn finished tied for second at 11-under in a group of seven players which included American Brittany Altomare, overnight co-leader Kim Sei-young of South Korea and New Zealand's Lydia Ko, who carded the day's lowest score of 66.
Kang, who started the final day one shot off the lead, failed to make any gains on the front nine and dropped a shot at the par-five fourth hole.
But the 26-year-old recovered with four birdies after the turn to finish 13-under overall at a breezy and overcast Qizhong Garden Golf Club.
Kang, ranked 29 in the world, added the Shanghai title to the Women's PGA Championship crown she lifted last year.
She later admitted having a "temper tantrum" after a sluggish front nine and credited her caddie for a remarkable turnaround on her way to the finish.
"After nine holes I had a temper tantrum," said Kang. "He told me to go off to the side and we did. Hit the bag, do whatever you need to do to let your anger out and start a new nine. That's what I did.
"I've been through so much just mental struggle that it's just been emotionally draining all year. I'm just finally happy and just working on my game properly."
Spain's Carlota Ciganda, who held a share of the lead heading into the final round, slipped to a tied-ninth finish after signing for a one-over 73.
