Stacy Lewis vaulted into a one-shot lead after posting her second consecutive three-under 69 in the second round of the LPGA Tour`s Swinging Skirts Classic on Friday.
American Lewis finished 36 holes at Lake Merced Golf Club at six-under-par 138.
"We knew it was going to be a long day," said Lewis who earned three victories in 2013. "That`s the way I took it, one shot at a time and tried to get the ball in the hole.
Second round play was stopped for 80 minutes because of a rain storm.
"That`s what I tried to do. Get it in the hole as fast as I could. Fortunately I was able to do that and make a couple putts."
First-round leader Karine Icher of France shot a one-over 73 and is tied with Kiwi Lydia Ko (71) for second place at five-under 139.
World number one Park In-Bee of South Korea tied the low round of the day with a four-under 68 to jump into a share of fourth with Lee Il-Hee (73) and Mika Miyazato (69) at three-under 141. Suzann Pettersen (72) is among nine players tied for seventh at two-under.
Pettersen was joined by P.K. Kongkraphan (68), Catriona Matthew (69), Kang Hae-Ji (70), Brittany Lang (71), Paola Moreno (71), Carlota Ciganda (72), Kim Hyo-Joo (73) and Jenny Shin (74).
Lewis, who began on the 10th hole, opened her round with six straight pars before rolling in back-to-back birdies at the 16th and 17th to move to five-under.
She birdied the eighth to reach six-under and parred the last hole.
Icher followed five straight opening pars with a bogey at the sixth to fall to five-under.
She parred her final four holes to finish at five-under.
"It`s a tough golf course," Icher said. "You can be quick in trouble, or if you`re playing well, like yesterday I did think it goes pretty well -- but today with the wind and the rain it`s definitely a tough day."