Moriya, the 2013 LPGA Rookie of the Year seeking her first tour title, fired a one-under par 70 while Ko shot 66 at Wilshire Country Club to finish level on nine-under 204 after 54 holes.

Seven-time major champion Park In-bee was third on 206 with South Korean compatriot Ji Eun-hee and American Marina Alex sharing fourth on 207.

Moriya opened with a double bogey and took another bogey at the par-4 sixth before turning her round around with a birdie at the par-4 eighth.

The 23-year-old sister of Thai star Ariya Jutanugarn eagled the par-4 14th and closed with a birdie at the par-3 18th to match Ko atop the leaderboard.

Ko Jin Young

Ko, 22, won 10 times on the Korean women’s tour, the last of those titles coming last October at Incheon in an LPGA co-sanctioned event. She added her second LPGA victory in February at the Australian Women’s Open.

Ko birdied the third and fifth holes and added another to start the back nine. She continued to surge with birdies at the par-3 12th and par-5 15th before her lone bogey at 16, which she answered with a birdie at 18.

Joining the co-leaders in the final trio on Sunday will be Park, whose back-to-back birdies at 15 and 16 spiced a 69.