World number one Yani Tseng, the LPGA Tour's dominant figure, birdied her final hole to end the second round of the Kraft Nabisco Championship with a one-shot lead in Rancho Mirage, California on Friday.
A winner in six of her last 12 LPGA events, the long-hitting Taiwanese fired a four-under-par 68 on another day of glorious sunshine at Mission Hills Country Club in the first women's major of the year.
Champion here in 2010 and fresh from consecutive victories on the U.S. circuit, Tseng mixed five birdies with one bogey to post an eight-under total of 136 on the Dinah Shore Tournament Course.
South Korea's Kang Haeji was alone in second, after carding a 68, with compatriot Yoo Sun-young (69) and Australian Lindsey Wright (71) a further stroke back at six-under 138.
Wright had joined Tseng at eight under when she sank a curling 30-foot putt to birdie the par-four 10th but she slipped back with a double-bogey at the 15th to finish two off the pace.
Two more Koreans, Choi Na-yeon (67) and five-times major winner Pak Se-ri (69), and Swede Karin Sjodin (67) were tied for fifth at five under.
The ominous sight of Tseng at the top of the leaderboard will have sent shock waves across the field at Mission Hills as the game's top player hunted a sixth major victory.
"To catch Yani is difficult," five-times LPGA champion Choi told reporters after compiling five birdies in a flawless display.
"When she's playing well, she looks like a very intimidating player. She played so well today and last week and two weeks ago. She's an amazing player right now."
Tseng had been disappointed with her opening 68 but she was much happier with the same score on Friday having negotiated slick greens that had quickened under a baking sun.
"Yesterday I had a couple of shots I just missed, and a couple of shots where I wasn't committed and I just hit it," said the 23-year-old, who has won four of the last eight majors
"But today, on every shot, I gave my 100 percent focus. The goal was the same, but I feel so much happier today.
"I still have two more days to go, and this golf course suits me really well. I heard tomorrow's going to be very windy in the afternoon, so I just need to be patient."
Tseng finished her second round in style with a one-putt birdie at the par-five ninth.
"It just made my day," she said. "It made me feel that I can relax and do something more fun. I was feeling just so happy."
It was not a happy day for some of the other big names on the LPGA Tour, however.
Norway's Suzann Pettersen, who finished a stroke behind the triumphant Tseng at the 2010 Kraft Nabisco Championship, and 2007 winner Morgan Pressel returned 74s to occupy the lower reaches of the leaderboard.
The cut fell at four-over 148 with 2009 champion Brittany Lincicome, who battled to a second-round 76, and fellow American Michelle Wie, after a 77, among those failing to advance.
(Reporting by Mark Lamport-Stokes in Los Angeles; Editing by Julian Linden and Nick Mulvenney)