Portugal Colonial - South Korean An grabs lead at LPGA Tour Championship

An reeled off three birdies in a row starting at the 11th hole and sank eight birdies overall to finish one ahead of Angel Yin, who made a long eagle putt from the fringe at the par-5 17th to seize second.

"I played well," An said. "My putting really good. The speed was good and the shape was good. I was just trying to make to focus a little bit more."

Americans Marina Alex and Allisen Corpuz shared third on 66.

The top 60 players in the season points chase qualified for the $11 million showdown with a $4 million top prize at Tiburon Golf Club in Naples, Florida.

An felt no extra pressure with the record payout for the season ender.

"It's about the same with the different tournaments. Just tournament is tournament for me. I just do my best," she said.

An, 28, managed her best LPGA finish earlier this season at Portland, where she made a hole-in-one in a runner-up effort.

World number 76 An birdied the second, fourth and par-5 sixth then closed the front nine with another birdie before her back-nine birdie streak and a birdie at 17.

Yin, ranked 34th, made bogeys at the second and fourth but then made three birdies in four holes, the par-3 fifth and eighth and par-5 sixth.

The 26-year-old American began the back nine with four birdies in five holes then added her eagle at 17.

"Started out a little bit rocky just because I was trying to adjust to the golf course -- playing quite difficult with the early winds," Yin said.

"It's a good head start for the big ol' prize we get at the end of the week. Hopefully I continue it and see how it goes on Sunday."

A fifth-place pack on 67 included Sweden's Linn Grant, France's Celine Boutier, Japan's Nasa Hataoka, Swiss Albane Valenzuela, Thailand's Ariya Jutanugarn and New Zealand's Lydia Ko, a two-time winner of the event.

"I capitalized on some good birdie opportunities," Ko said. "It was really steady."

Top-ranked Nelly Korda, seeking her eighth title of the year, opened with a level-par 72 to stand eight off the lead in a share of 44th.

Korda, who has already clinched the LPGA Player of the Year award, opened with a birdie but stumbled with back-to-back birdies at three and four.

The 26-year-old American birdied the par-3 eighth before taking a bogey at 10 and a birdie at 17.

X.M.Francisco--PC