South Korea's Ko leads Australian Open by two shots

Adelaide (Australia) (AFP) - South Korea's Ko Jin-young fired a nine-birdie opening round of 65 to lead the women's Australian Open by two shots at Kooyonga in Adelaide on Thursday.

Ko, 22, the world number 20 and a winner of 10 tournaments on the Korean tour, reached the turn at three-under and rolled in six more birdies on the back nine to gather in a cluster of players who had held the lead at four-under.

Ko joined the lead with a birdie at the 16th, birdied again to lead outright at the 17th before repeating the performance at the 18th to lead by two strokes at seven under.

She had nine birdies for the day, two bogeys and shredded the more difficult back nine in 31 shots, with five birdies in the last six holes.

Among those on four-under was former world number one Lydia Ko, who has been under fire for making another series of changes to her team in the off-season, but played brilliantly for a bogey-free round.

Ko Jin-young leads 2013 Open champion and compatriot Jiyai Shin, who followed up her win in Canberra last week with a five-under par 67.

Two other major winners -- American Mo Martin and Korean Yoo Sun-young -- as well as 17-year-old Japanese amateur Suzuka Yamaguchi, a recent Australian Amateur champion, are in the group at four-under par.

Ko, the 20-year-old New Zealander, has again switched to another coach and caddie and has had 11 caddies since turning pro five years ago.

"I'm trying to make the decisions where I think it's the best for me in my career," Ko told reporters after her opening round.

"Sometimes, I think 'hey, maybe I shouldn't have done that'. But I feel like I made the right decisions.

"All I can do ... is do what I think is best for me and, sometimes, not everybody is going to agree."

Ko last year lost her world number one ranking amid her first winless LPGA season since 2012.

Ko is now working under Ted Oh and added: "Hopefully, this one does go a long way."

She birdied four of her initial 10 holes to be among a group of 10 golfers on four under 68.