Yin Ruoning got her campaign for an unprecedented third consecutive win off to a strong start on Wednesday when the Shanghai rookie shot a four-under 68 in the first round of the Mitsubishi Heavy Industries Orient Masters, good for a one stroke lead.

Playing under severely hot conditions in Fujian province at Orient Xiamen, Zhang Yunjie was one stroke back at the RMB500,000 (73,400 US dollars) tournament, the third leg of the China LPGA Tour season.

Zhang Weiwei, last year's CLPGA Tour Order of Merit winner, was two strokes off the pace after a two-under 70, tied with Li Dongmei, Zhang Jienalin and Miranda Wang Xinying.

Yin, who won the opening two legs of the CLPGA Tour in her first two starts as a professional, came out firing at Orient Xiamen with four birdies over the first seven holes. After a bogey four at the 155-yard eighth hole, the only shot she would drop on the day, she picked up another shot with a birdie four at the 500-yard 13th hole.

"I thought four-under must be a leading score while I was warming up on the driving range this morning. I did it at the end of the day. My whole game was sharp. I hit it very close. The weather was very hot but better than yesterday. There was a little wind out there."

The 17-year-old Yin, who also won the CLPGA Tour Qualifying Tournament in January as an amateur, lamented her lone bogey at the par-three.

"I accept making bogey, but this bogey is not acceptable because I was not far away from the pin. Tomorrow, I will keep the same plan and try to have a bogey-free round."

Zhang Yunjie, who was tied fifth last week at the Golf Liquor Zhuhai Golden Gulf Challenge, continued her good form with a bogey-free round that included three birdies on the front nine.

"It's a good day today. I shot a bogey-free round," said the 22-year-old Hainan native. "The grass is thick. It's hard to play when you are against the grain on the fairway. It's easy to be shorter than you expected. I played well on the front nine, but not so well on the back because of some bad lies."

After winning a record four times last year, Zhang Weiwei said she saw a glimmer of hope for her game as she started with a birdie. In the first two legs this year she has finished tied fifth and eighth respectively.

"I started with a birdie today and expected that this was my time. But it's too hot out there and I lost my focus," said the 23-year-old Hubei native. "I didn't make birdies over the first two par-fives where I think I can make birdie. Instead, I made two bogeys in a row [from the sixth hole] with two three-putts. It's not the best start. I could make more birdies. But you can't complain a lot about two-under."

Wang, playing in her second tournament as a pro, looked good through 13 holes as she got to four-under. She then struggled down the stretch with two bogeys over the last three holes, including one at the 375-yard 18th hole.

"It's been a long time since I played here, maybe four or five years. My plan was to be conservative. I could be more familiar with this golf course," said the Beijing native who recently graduated from Duke University in North Carolina.

"I played great and had four-under during the round, but over the last three holes I hit two errant tee shots and made two bogeys. But there are two rounds left. I will try to be aggressive tomorrow."

Zhang Yue, Chen Siyan, Fan Shuangshuang, Zhang Junyuan and Yin Xiaowen were the top amateurs as each opened with a round of even-par 72 to sit together at tied 12th in a group of eight players.