The 17-year-old felt the full brunt of Royal Birkdale today as she carded a four-over 76. She started with a bogey but made birdies at the second and third holes before her round fell apart.
There was a triple bogey at the par-four eighth, a double at the par-four 16th, while she also dropped a shot on the 12th and 17th holes.
Ko made birdies at 15 and 18, which saved the day from being a complete disaster as she slipped to a share of 34th, 10 strokes back from leader Mo Martin (-10) who fired her second-straight round of 69.
Ko began with an even-par 72 yesterday, which left her in contention in the early stages, but the task of overhauling this deficit may be too great for her during the next two rounds.
Martin, the world No 99 who has never won on the LPGA Tour, showed impressive control to navigate the tricky course in Southport, England and was the only player to shoot under 70 in both opening rounds.
"It's been a fun day," Martin told local media. "It's always nice when your plan pans out. Earlier in the week my caddy and I worked out where the widest parts of the fairway were and where I would have the best approaches into the greens and those are what we have been aiming at."
Martin has a three-shot lead over Spain's Beatriz Recari and Korea's So Yeon Ryu who are both at three-under.
American Michelle Wie, who won last month's Women's US Open, was among the big names to miss the cut after rounds of 75 and 78.
"I'm extremely disappointed how I played," she told reporters. "But, you know, there's nothing I can do about it. I'm just going to think about what I did wrong here and see how I can improve."
Kiwi Cathryn Bristow, who began with a horror 13-over 85 yesterday, only gradually improved in her second-round with a 10-over 82 as she also missed the cut.
- by Daniel Richardson of APNZ
