Lewis guns for golf No. 1 as she leads HSBC Women's

The world number four started the day two back from overnight leader Azahara Munoz, but she holed three birdies on both the front and back nine to head into the weekend two shots clear at Singapore's par-72 Sentosa Golf Club.

Snapping at the heels of her 11-under-par total of 133 were Choi Na-Yeon, the world number two, fellow South Korean Chella Choi, 17-year-old Thai sensation Ariya Jutanugarn, and Paula Creamer, who is battling whiplash injuries from a car crash last week.

First round leader Munoz, of Spain, and South Korea's Yoo Sun-Young were also among the six players bracketed at nine-under-par 135.

Taiwan's Tseng, who has topped the rankings for 107 weeks but is now defending a dramatically reduced lead, got off to a bad-tempered start when she mis-hit her first tee shot and gesticulated at a photographer.

The 24-year-old then double-bogeyed the fourth hole and couldn't repair the damage, ending the day with 73 and eight shots adrift of Lewis, with her hopes diminishing of a first win in nearly a year.

Lewis led last week's Honda LPGA Thailand before being overhauled on day three by Ariya, and she will be looking over her shoulder at the young Thai who matched her score of 66, highlighted by a sizzling iron shot to one foot on the 18th.

The 28-year-old American said a shift in her putting grip and a reminder to stay relaxed could help her stay in front as she seeks the sixth LPGA victory of her career.

"I've had leads and each one is a little bit different. Last week my putter just went sideways, I don't know what happened," she said. "But I feel a lot more comfortable with my putter this week.

"You just can't try too hard, and the biggest thing for me is being very patient. You can't force things and I think last week I definitely was trying to force some putts and hit them too hard and through breaks."

Lewis, who spent most of her teenage years in a back brace to correct a curve in her spine, also said her goal remained being crowned world number one, which now looks a realistic prospect after Tseng's dominance faded over last season.

"Middle of last year, one of my goals was to track down Yani -- it still is," she said. "Each week you kind of have to build off of it. I didn't play well last weekend but I still finished third and that helps me in that move to number one.

"So I just keep chipping away at it and giving myself chances to win. I've been doing a good job of that, and I just keep knocking on the door."

Creamer, the world number 13, has done an astonishing job to be vying for the lead considering Sunday night's crash in Bangkok which left her battling neck, back, arm and shoulder problems, and unable to play a practice round.

"It takes me a little while to get used to my arm out there. It's really my shoulder that's kind of bugging me... it gets loosened up as the day goes on," she said.