Shin Ji-yai finally claimed the title after a dozen shots in the Japan LPGA this season.
In the Nichirei Ladies that ended at the Sodegaura Country Club in Chiba Prefecture on Sunday, she finished at 12-under 204, four strokes ahead of Hikari Fujita and Rumi Yoshiba who shared second place.
She won 14.4 million yen of prize money with her sixth career title in the JLPGA and her first win in four years on tour since the Mizuno Classic in November 2010.
Shin topped the global rankings in 2010 when she won the 11th win of her career in the U.S. LPGA Tour.
But late last year, she decided to focus on the Japanese tour and hoped to become the first player to sweep the money lists on the Korean, Japanese and U.S. tours. She also said her playing style is better suited to Japanese tournaments.
She purchased a small apartment in Tokyo and trained by herself without any sponsorship deals.