China's Feng Shanshan shifted into cruise control at the Buick Championship on Saturday as the world No. 5 carded a conservative three-under 69 to open up a seven-shot lead through three rounds of the China LPGA Tour-Ladies European Tour co-sponsored event.

The U.S. LPGA regular, a winner of 13 tournaments worldwide, was at 15-under 201 after 54 holes at Shanghai Qizhong Garden Golf Club.

Norway's Marianne Skarpnord (69) and South Korean Kang Hyeon-seo (69) were a distant equal second at the 600,000 U.S. dollars championship, while Dane Nicole Broch Larsen had the best score of the day at 65 on the strength of two eagle-threes to sit fourth, nine shots off the pace.

Starting the day with a six-shot lead, Feng opened and closed her round with bogey fives, with five birdies in between in the windy conditions. With the final two rounds of the Buick Championship being a pro-am, she said the format had initially made her a bit nervous.

"It's my first time to play with an amateur in a real professional tournament. That was fun. After a few holes my partner was playing very good. He saved me two shots on the first three holes. He did very well."

The Guangzhou native, a brand ambassador for Buick, said with such a commanding lead she couldn't worry about what other players were doing in the final round.

"Coming into the tournament I never set any goals. I came just because I wanted to come back to China to play a tournament and also support my sponsor Buick. So it doesn't matter how I play this week as long as I tried my best. At beginning of the tournament, someone asked me what score will win. I say it should be 15-under. But tomorrow there will be someone (shooting) crazy. I'm just going to focus on my own game and shot by shot."

Skarpnord, the winner of the Victorian Open on the Australian ladies tour in February, came out on fire in the front nine, registering five birdies, including four consecutively starting at the sixth hole. On the back nine, the putter went cold as she was one-over after a bogey-four at the 16th hole.

"I've been putting well on the front nine, both yesterday and today, but on the back nine it's like it goes cold and I don't make anything. I had four or five putts within 3.5 metres on the back nine and didn't make any of them, so it was not completely useless but could have been a lot better today."

The 29-year-old Skarpnord, who is engaged to European Tour pro Richard Green, said she wasn't even thinking about catching Feng tomorrow. Instead, she would be playing for second place as the forecast is calling for overcast conditions with the wind set to pick up.

"I don't mind if it's windy. I think that would be good for me, coming from Norway and the cold and windy weather."