Yani Tseng blistered the back nine in 29 en under 65 and a share of Thursday's first-round lead at the LPGA Founders Cup.
Tseng, the No. 1 player in the world, and Hee Young Park are tied for first place at the Wildfire Golf Club at JW Marriott Phoenix Desert Ridge Resort & Spa.
Tseng could've been in first by herself, but she actually looked human and missed a short putt.
Park couldn't save par from over the green at the ninth, her 18th hole on Thursday. That bogey dropped her to seven-under and Tseng had five feet for birdie on the 18th green.
Tseng didn't play enough break and walked off with par, but also with a piece of the lead.
"Tried too hard on the last hole," admitted Tseng.
Jiyai Shin shot a six-under 66 and is alone in third.
This event honors the founding members of the LPGA Tour. Several were in attendance Thursday and were treated to a brilliant showcase by the newest legend in the making.
Tseng made the turn at even-par after a bogey at four and a birdie at five. She parred five in a row from the sixth, then went on a spectacular run to ascend to first.
Tseng birdied the par-five 11th, then rattled off back-to-back birdies at 13 and 14, the last coming from over 20 feet. At the par-five 15h, Tseng hit an amazing three-wood that rolled up to five feet, then holed the eagle putt to get to five-under for the championship.
The No. 1 player in the world didn't stop.
She knocked a wedge inside four feet at the 16th to set up another birdie. Tseng hit a superb tee ball to three feet at the 17th and made that putt to reach minus-seven.
At the closing hole, Tseng hit a beautiful seven-iron five feet short of the flag stick. The putt stayed above ground, but Tseng, already a winner this year in Thailand, did enough for a share of first.
"It was fun," said Tseng. "I was patient out there, hung in there and tried to make as many birdies as possible."
Park, who finished 12th on the money list last year and won the season-ending CME Group Titleholders, flew out of the gate with back-to-back birdies at 10 and 11. She added consecutive birdies from the 15th, but made her move on her second nine.
Park birdied the par-five seventh and picked up her second in a row at three. She made birdie at the par-five fifth and moved into sole possession of the lead.
Park birdied the eighth hole to build what appeared to be a cushion, but that fell thanks to Tseng's rise and a Park hiccup at nine. She missed the green long and left and didn't get up and down.
World No. 2 Na Yeon Choi, Hee Kyung Seo, Karen Stupples and Pernilla Lindberg share fourth at five-under 67.