Shin's iron play was the key to her round. In a space of six back-nine holes all her shots to the green were inside four feet.
SHIMA, Japan (AP) -- Shin Ji-yai showed up at chilly and wet Kinetsu Kashikojima with some warm clothes and a sizzling iron game.
"I just brought my warm gear," said Shin, the young South Korean star who won the Women's British Open in August at Sunningdale.
"I had my gloves, my warm hat and my jacket. Some parts of the course it rained today, so the rain was very cold, but the wind was not much," she said.
Making her fifth start of the year in Japan, Shin shot a bogey-free 66 on Saturday to take a two-stroke lead in the Mizuno Classic. She had a 10-under 134 total with a round left in the event sanctioned by the LPGA Tour and Japan LPGA.
"Today, it just felt very comfortable with how I played," Shin said. "I am just happy with how I played my round."
Shin birdied both par 5s on the front nine, chipping to 2 feet on the par-5 first and a foot on the par-5 seventh. She then showed off her iron play in two back-nine birdie runs, hitting a 6-iron to a foot on 10, a 5-iron to 3 feet on 11, another 6-iron to inches on 15 and a 9-iron to 4 feet on 16.
"My iron shots were good," Shin said.
Japan's Mayu Hattori, coming off a victory last week in the JLPGA's IDC Otsuka Ladies, was second after a 69. The first-round co-leader played the back nine in 3 under after making the turn at even par.
"I guess I felt some pressure after being in the lead," Hattori said. "I settled down and played a lot better after the front nine."
South Korea's Lee Jee-young and Japan's Shiho Oyama three strokes back at 7 under.
"On the 15th hole, one of the spectators said that my ball went in the cup," Oyama said. "I got all excited, but it didn't actually go in, and I was embarrassed. My irons were good, except my driver didn't go so far today."
Lee matched Oyama with a 68.
"It was really cold this morning, so I had to be patient with my game," Lee said.
Shin tied for 17th last week in the LPGA Kolon Championship in South Korea.
"Last week, everyone was focused on me, so it made me nervous," Shin said. "I think more nervous last week than this week. This week, I love coming here to Japan. I just feel more comfortable here."
Divots:@ Defending champion Momoko Ueda, the first Japanese player to win the event in nine years, was even par after a 74. ... Japanese star Ai Miyazato also was even par after a 73. ... American Morgan Pressel followed an opening 75 with a 70 to get to 1 over. ... Karrie Webb, the 2006 winner, was 3 over after a 75.