South Korea's Ahn Sun-ju turned on the style in the final round to collect her second win in as many weeks at the Nitori Ladies on Sunday.
A day after her 26th birthday, Ahn fired off seven birdies in a blemish-free round of 65 to turn a two-stroke deficit into a two-shot win at Katsura Golf Club.
Ahn finished ahead of Taiwan's Teresa Lu at 11-under 205 and collected ¥18 million in prize money for her 13th career victory on the Japan LPGA Tour.
"I turned 26 yesterday and this is a great present for me," said Ahn, the Japan LPGA money-title winner in 2010 and 2011. "I wasn't hitting well with my driver but once I tried to swing with more confidence, things improved."
"I played the round without making any bogeys and feel like I have regained my confidence," she added.
Lu also shot a 65 to finish alone in second place, while Yuko Fukuda carded a 67 and followed in third, two shots further back.
Ayako Uehara and last season's money winner, Jeon Mi-jeong of South Korea, tied for fourth at 6 under.
Overnight leader Lala Anai came up empty in her bid for a first win on tour as she stumbled with a 74 and wound up in a six-way tie for seventh.