If you want to know the secret to shooting the best round of your life, Becky Kay has the answer.

“Japanese sweets.”

"Oh, and making plenty of birdies”.

The Gold Coaster rewarded herself with a "treat" after each birdie, leading to an opening-round course-record 64 at The Royal Golf Club in Japan today.

A bogey-free eight under finish sees the 20-year-old take the outright lead after round one of the Women’s Amateur Asia-Pacific, with defending champion Atthaya Thitikul a single shot back.

“Eight under is my best round and it’s pretty special,” the Queensland Academy of Sport athlete said.

“First round of a huge tournament so I’m really stoked just to be in contention.

“I think it was a chocolate bar. Honestly, I’m don’t know what I’m eating here because it’s in Japanese, but it was yum.”

Kay was brilliant in peeling off six birdies in her opening nine holes (10-18) to string out the field early.

The World No. 135 managed to defy the “potato chip shaped greens”, making several clutch putts including a 35ft bomb on the par-4 second hole.

“I did hole long putts, but I did find that if you missed them, they were going about four feet past and then it was a slippery one coming back," she said.

“My last hole, I put (my first putt) to four-foot amd it was downhill right-to-left, got my heart beating a bit."

With the winner receiving invitations to two majors - Women’s British Open and the Evian Championship - and the Augusta Women's National championship, Kay is well aware of what a great start means.

“I’ve put myself in a position where I actually have a chance of playing two majors, and that's my dream come true.

“I know there's so many good players here, so I just have to stick to my own game and see what happens.”

Australia’s highest-ranked female amateur Grace Kim had a slow start to the day, dropping a stroke early on the second hole before firing home with three birdies for a two-under-par 70 round at T12.

“I managed to scramble a lot today,” the recent Karrie Webb Scholarship recipient said.

“Missed a couple of shots but got myself with up-and-downs.”

West Australian Maddison Hinson-Tolchard managed to overcome “huge nerves” over her opening tee shot to sign for an even par round.

Also at that mark is Doey Choi and Julienne Soo, with Soo unfortunately offsetting four terrific birdies with matching bogies.

Steph Kyriacou fought hard but was unable to convert putts, finishing one over.

Full leaderboard.