Yoko Inoue shot a 5-under-par 67 Thursday to set the early pace after the first round of the Japan LPGA Championship, the first "major" of the year on the Japanese women's tour.
Inoue, an eighth-year pro who has won four tour titles, birdied three of the final four holes in a bogey-free round at Rope Club in Tochigi Prefecture as she took a two-shot lead over Riko Higashio, Kaori Harada and Mihoko Takahashi.
With solid drives off the tee and good iron play, Inoue hit 16 greens in regulation to set herself up for her first victory since winning two tour events in 1999.
"I just tried not to make a bogey throughout the round. Probably this is the finest round of my career and I really enjoyed it," said Inoue, who has been plagued with back pain that dropped her to 57th in last year's money list with just one Top-10 finish.
Higashio and Harada matched each other with three birdies against no bogeys, while tour rookie Takahashi had four birdies.
Chieko Amanuma and Yuri Fudo, the top two players on this year's money list, head a group of 12 tied for third at 70.
Miyuki Shimabukuro, winner of last week's Fujisankei Ladies Classic, had a 71. U.S. LPGA Tour regulars Akiko Fukushima and Hiromi Kobayashi shot 72 and 73, respectively.