Published: Oct 07, 2011 8:59 AM EDT
Updated: Oct 08, 2011 6:30 AM EDT

INCHEON, South Korea (AP) - Yani Tseng lived up to her top-ranked billing by shooting a seven-under 65 on Friday, taking the lead after the first round of the LPGA Hana Bank Championship.

The world No. 1 had ten birdies and three bogeys to take a one-stroke advantage over Chella Choi, who capitalized on early mild conditions at Sky 72 Golf Club to set the early pace at six-under.

Two-time defending champion Na Yeon Choi was in a tie for third place along with Sandra Gal of Germany at five-under.

American Paula Creamer and Swede Sophie Gustafson were part of a group of six players in a tie for fifth place at 4-under par, along with Koreans Meena Lee, Hee Young Park, Jimin Kang, and Mi Hyun Kim.

Tseng overcame a poor start, bogeying two of her first three holes.

"I felt a little off and my tempo was off in the beginning," said Tseng. "I tried to figure out what to do with my swing."

Once Tseng figured it out, the world number one went on a torrid streak with birdies on seven of her next 11 holes.

After missing a three-footer for par on number 16, Tseng reached the green in two on the par-5 18th hole for a birdie to reach seven-under par.

Tseng could not remember the last time she had ten birdies in one round on Tour. She could have gone even lower considering her three bogeys all came on three-putts.

The Taiwan native has already won five tournaments this year and is on pace to sweep the LPGA's season-ending awards.

Among other notables, 2007 champion Suzann Pettersen and former world number one Jiyai Shin were at even par, along with Americans Cristie Kerr and Michelle Wie.

The winner of the inaugural 2002 edition of this tournament, Se Ri Pak, was off the mark with a four-over 76.

After this week, the LPGA Tour heads to Malaysia and Taiwan and then wraps up its Asia swing with the Mizuno Classic in Japan in early November.