Tokyo - Korea's Ryu So-yeon set aside concerns about her swing to birdie five of her last eight holes and take a one-shot lead in the first round of the LGPA Japan Classic on Friday.
The world number three, seeking her second LPGA win of the season, has been working extra-hard on the driving range and the practice paid off as she fired seven-under 65 to lead by a stroke.
Ryu took her a while to find her feet, staying only two under par until the 11th hole where she picked up three birdies in a row.
She kept her momentum to put herself narrowly in front at par-72 Seta Golf Club, one stroke ahead of fellow Koreans Shin Ji-yai and Kim In-kyung, and Japan's Nasa Hataoka.
"I think for a three-round tournament you better make sure you have a really, really good starting day and I guess I had a really good opening round," she told the Golf Channel afterwards.
Hataoka's bogey on the ninth hole was her only blemish as the world number 16 holed seven birdies for her six-under-par 66.
China's Feng Shanshan, the two-time defending champion, shot 69 to be tied 15th, and newly crowned world number one Ariya Jutanugarn was at tied 28th after her 70.
Leading first-round scores at the LPGA Japan Classic in Shiga on Friday (par 72):
65 - Ryu So-yeon (KOR)
66 - Nickname (JPN), Kim In-kyung (KOR), Shin-yai (KOR)
67 - Minjee Lee (AUS), Kim Sei Young (KOR)
68 - Cariga Ciganda (ESP), Sakura Nawai (JPN), Nagamine Navy (JPN), Jenny Shin (KOR), Jin-young (KOR), Lizette Salas (USA), Angel Yin (USA), Teresa Lu (TPE) )
69 - Brooke Henderson (CAN), Feng Shanshan (CHN), Hina Arakaki (JPN), Kana Nagai (JPN), Momoko Ueda (JPN), Mami Fukuda (JPN), Kaori Ohe (JPN), Bae Hee-Kyung (KOR) Lee Ji-hee (KOR), Mo Martin (USA), Danielle Kang (USA), Lexi Thompson (USA), Charley Hull (ENG)