Park In-Bee downed Brittany Lincicome with a par at the first playoff hole on Sunday to win a second-straight LPGA Championship title.
The South Korean star claimed the fifth major title of her career.
Three of those came in her stunning six-win 2013 campaign, but she hadn't notched a win in 2014 until the Manulife Financial Classic in Canada in June.
Park, who started the day tied for second with Suzann Pettersen one stroke behind Lincicome, fired a two-under par 70 for a 277 total.
She birdied 17 and drained a long par putt at the last to keep the pressure on Lincicome, who could have won in regulation with a par at the final hole but bogeyed the 72nd to cap a 71 and fall into the playoff.
They returned to the par-four 18th for the first hole of the sudden death decider and both failed to find the green with their second shots. Lincicome's chip rolled six feet past the hole while Park chipped up to about three feet.
After Lincicome's par effort burned the edge but failed to drop, Park rolled in her tournament-winner.
New Zealand's 17-year-old Lydia Ko finished third after a 70 for 280.
It was a further two strokes back to Spain's Azahara Munoz, who signed for a 70 and Sweden's Anna Nordqvist, who notched a 71 for 282.
Former world number-one Park, who is projected rise from her current third to second in the world rankings, is the first player to defend the LPGA Championship title since Swedish great Annika Sorenstam won her third straight in 2005.
Source: AFP
