Ai Miyazato tied the tournament record Thursday with a 9-under 63 to grab the lead after the first round of the RR Donnelley LPGA Founders Cup.
A runner-up at this event last year, Miyazato holds a 2-stroke lead over Jee Young Lee, who carded a 7-under 65 at Wildfire Golf Club at JW Marriott Phoenix Desert Ridge Resort & Spa to sit alone in second place.
"I hit the ball well and my putting was really good," said Miyazato. "I think I had good course management as well and I could control myself really well, too, so it was a good day."
Pornanong Phatlum (66), Gerina Piller (66), Candie Kung (66) and Brittany Lang (66) share third place at 6-under, while Katherine Hull-Kirk (67), Sandra Gal (67), Jiyai Shin (67) and Lexi Thompson (67) sit a shot back of them in seventh at 5-under.
Last year's winner, Yani Tseng, carded a 2-under 70 in her first round to take a share of 39th place.
Miyazato opened her bogey-free round with a birdie at the first followed with three straight pars.
She then birdied at the fifth before hitting the turn at 3-under following another birdie at the eighth.
After adding another birdie at the 11th, she was able to race up the leaderboard by picking up five strokes over a four-hole stretch.
The hot streak started with a birdie at the 14th that was followed by an eagle at the par-5 15th.
She carried that momentum with consecutive birdies at the 16th and 17th to move further ahead before ending her day with a par at the last.
"You know, it's just beautiful out there," Miyazato said about the course. "It's just always nice to play in this tournament, it's very enjoyable, and I just had a good feeling this morning."
Lee started on the back nine and opened strong with back-to-back birdies at the 10th and 11th, but then stumbled to a bogey at the 12th.
However, she gained that shot back plus another with birdies at the 13th and 14th, and then raced out to 6-under on the day by reeling off a streak of three straight birdies from the 16th.
A bogey at the first halted her momentum, but she was able to counter that with a birdie at the second.
She then rolled in her ninth birdie of the day at the fifth to pull within striking distance of Miyazato with four holes to play, but she could get no closer as she closed out her round with four straight pars to remain two strokes back.
"I had good tee shots and irons, and I had a lot of birdie putt," said Lee. "I feel really good today and I want to keep it up."
NOTES: Miyazato also tied her career-low round, which she shot at the 2009 CN Canadian Women's Open ... The world No. 1 Tseng could be overtaken in the rankings this week by either Na Yeon Choi or Stacy Lewis. Choi will replace Tseng with a first-place finish and Tseng finishes fourth or worse, and Lewis will take the top spot with a victory and Tseng finishes third or worse ... Lewis (68) is tied for 11th place at 4-under, while Choi (69) is in a large group tied for 21st at 3-under ... Jane Rah recorded a double eagle at the 15th ... Jennifer Gleason hit a hole-in-one at the 171-yard par-3 14th.