Stacy Prammanasudh, one of four first-round leaders alongside of Kerr, managed a 1-under 71. She shares second place with Seol An Jeon (70) and Heather Daly-Donofrio (68) 4-under-par 140. Mi Hyun Kim is one stroke further back after a 2-under 70.
Kerr began her day on the 10th tee at Las Vegas Country Club. She birdied the par-5 hole after chipping to 1-foot to get to minus-4. She then parred the next nine holes.
She picked up back-to-back birdies from within 15 feet from the second to extend her lead. Kerr birdied the par-5 sixth after dropping a wedge within eight feet. She two-putted from 45 feet for birdie at the par-5 ninth to close out her round.
'I had a good day with really solid ball striking,' Kerr said. 'I hit one or two drives left, which I need to go work on. But overall I hit the ball much more solidly today, and I had a lot of opportunities for birdie. I was real calm the whole day and just tried to play within myself, and once I saw I had the lead I said let's see how far in front I can get.'
With the three-round event ending on Saturday, Kerr will attempt to pick up her first win since the 2002 Longs Drugs Challenge.
'I think I'm playing the course a little bit better,' said Kerr, who shared second place here last year. 'I am a year older. I have got much more experience under my belt. So I look at things a lot differently than I used to. I know I need to stay patient and just play as well as I can. That's all you can really do, right?'
Daly-Donofrio scorched the back side, her opening nine. She drained back-to- back birdies from the 10th before birdieing the 14th. She again made two straight birdies from the 17th to get to minus-5.
The front side was not as kind however. Daly-Donofrio bogeyed the first, but erased that mistake with a birdie at the fourth. She dropped a shot at the very next hole to drop back to 4 under.
The 34-year-old birdied the seventh, but again stumbled to a bogey at the next to fall into a share of second.
'It played a little bit easier this morning than it did yesterday afternoon,' said Daly-Donofrio. 'I was the last group off yesterday and it was much windier yesterday afternoon than it was this morning. It's still very gusty and you still have to pay attention to it.'
Jeon had a steady round. She opened with three straight pars then dropped in back-to-back birdies from the 13th. The Korean parred the remaining 13 holes to remain in a share of second place.
Prammanasudh, who earned her tour card as the leading money winner on the Futures Tour in 2003, also opened her round on the back nine. She traded a birdie for a bogey over the opening two holes and then birdied the 12th as well.
The 24-year-old dropped another stroke on No. 14, before four straight pars to head to the front side at minus-3.
There, she picked up her third birdie of the day at the par-3 third. Prammanasudh stumbled to her third and final bogey of the day at the par-4 fifth. She took her share of second with a birdie at the sixth.
Juli Inkster posted a 4-under 68 to move to 2-under-par 142. She is joined in sixth place by Danielle Ammaccapane, Kraft Nabisco Championship winner Grace Park, Moira Dunn and rookie Reilley Rankin.
Tour rookie Aree Song and amateur In-Bee Park pace a group of 13 players at 1-under-par 143.
The cut line fell at 5-over-par 149 with 88 players advancing to the final day. Among those who missed the cut were Christina Kim (151), reigning U.S. Open winner Hilary Lunke (152) and Hall Of Famer Amy Alcott (152).