Golf: Kiwi Lydia Ko plummets down leaderboard after disappointing second round at LPGA's US Open

Kiwi golfer Lydia Ko has plummeted down the leaderboard, after a disappointing second round at the US Open in San Francisco.

Ko carded a four-over 75, including three bogeys and two double bogeys, to fall to four-over par, 10-shots behind outright leader Yuka Saso from the Philippines.

The Kiwi started her round at even par and made a bright start with a birdie at the par-four second, but immediately gave the shot back with a bogey at the fourth. 

The 24-year-old rounded out her front nine with a disastrous double bogey at the par-four ninth to make the turn at two over. 

Ko's back nine was a mixed affair, starting with a birdie at 10, but immediately dropping a shot at 11. 

Her round went from bad to worse at the par-four 14th, where she recorded her second double bogey of the day. 

Ko's colourful round continued with a birdie at 15, before picking up her third bogey of the day at the par-four 18 to end her second round four-over par, just two shots inside the cut line.

She struggled off the tee, hitting only seven of 14 fairways, and with her iron in hand, she made only nine of the 18 greens in regulation to leave her scrambling for most of the round.

Ko sits in a 12-way tie for 36th with China's Yu Liu and Xiyu Lin, Americans Jenny Coleman, Jessica Korda and Lauren Stephenson, Spain's Maria Parra, France's Celine Boutier and Celine Herbin, Canadian Brooke Henderson and Korean So Yeon Ryu. 

Saso leads the tournament at six-under at the halfway stage, one shot ahead of Korean Jeongeun Lee, with American Megan Khang and amateur Megha Ganne are at four-under. 

Kiwi Amelia Garvey shot a second-round eight-over 78 to sit 11-over par and miss the cut in her second US Open - her first Major as a professional.  

Ko took a break from golf at the start of May, missing the Pure Silk Championship in Virginia and a Las Vegas matchplay event to prepare for the US Open.

Ko hopes to win her first Major since 2016, with her last triumph coming at the 2016 ANA Inspiration.