CHONBURI, Thailand (AP) -- Lexi Thompson had two eagles in an 8-under 64 Thursday to take a one-stroke lead over Q Baek at the LPGA Tour's Thailand tournament.
Amy Yang, the defending champion, shot 66 and was two strokes behind after the first round. Two golfers were tied for fourth after opening 68s - Azahara Munoz and Jenny Shin.
"Two eagles definitely helps out the scorecard," Thompson said. "We couldn't have asked for better conditions, weather-wise and golf course, so just happy to be out here."
The 20-year-old Baek won her first and only LPGA title on home soil in South Korea in 2014. She had an eagle and five birdies in her round of 65.
Currently ranked No. 4, Thompson could overtake No. 3 Stacy Lewis as the top-ranked American with a win this week in Thailand and become the first American to win the event in its 10-year history.
"I think I was just very confident out there," Thompson said. "I committed to all my shots, just aiming at pins and focused on doing my routine, staying relaxed, and I think that's what helped me out the most."
She got off to a quick start with an eagle at the par-5 first hole, followed by two more birdies and another eagle on the par-5 seventh to make the turn in 30.
Thompson bettered her low round at Siam Country Club's Old Course by two strokes and finished one stroke away from matching the course record of 63 after missing a birdie putt at the last.
Thompson is playing with a new driver this week, and said she used it on nearly every hole, hitting 11 of 14 fairways.
"I've been trying to work into it for probably the last few months, and just trying to find a shaft that works for me, and finally found something I'm very comfortable with," Thompson said.