Lydia Ko will need a big weekend to defend her title at the Kia Classic on the LPGA Tour.
Ko has started her title defence with a two-over par 74 to sit in a share of 81st, one shot outside the projected cut line and eight shots off the lead.
It could have been worse for the 19-year-old, who was at four-over par with two holes remaining but scrambled two birdies to close her round at a slightly more respectable score.
Ko shot 19-under par to win the event by four strokes in 2016, and will require a big bounce back to make up ground on co-leaders Mo Martin, In Gee Chun and 2015 champion Christie Kerr at six-under par.
World number two Ariya Jutanugarn was also struggling, alongside Ko at two-over par.
Three Kiwis are also in action on the PGA Tour, at the Puerto Rico Open.
Steven Alker and Tim Wilkinson are both at one-under par in a share of 71st, while Danny Lee carded a three-under 69 to be in tied 29th.
Trey Mullinax leads the tournament at nine-under, with the first round yet to be completed because of lightning.
The tournament is missing the PGA Tour's usual big names, who are all playing at the World Golf Championships match play event in Texas.