Lydia Ko sits in a share of fourth place after shooting a four-under 68 in the opening round at the Kia Classic in Carlsbad, California.

Ko is one shot behind three players tied for the lead - American Brittany Lang, Ali Miyazato of Japan and England's Jodi Ewart Shadoff.

The world number one didn't have the best of starts to her round with a bogey on the opening hole before firing five birdies on the back nine.