Lee Ann Walker-Cooper carded a 4-under 68 on Thursday and is alone in second place at 6-under-par 138.
Miyazato also played poorly in the early going Thursday with two bogeys in her first four holes. She atoned for those mistakes the rest of the round as she collected five birdies.
On a day when wind reached 10-15 miles per hour, Miyazato complained about another problem.
'The wind was tough, but the pin placements were also difficult,' said Miyazato through a translator. 'My goal for everyday is to shoot 2 under, but I have been able to clear that goal the first two days and I just want to keep on doing my best.'
Miyazato won six times on the Japan LPGA Tour, but will not settle for her tour card. She wants to win the tournament outright, sparked by a conversation with this year's LPGA Tour Rookie of the Year.
'I was told by Paula Creamer when I was in Japan that I need to finish first, so I think I do want to win,' said Miyazato, referring to the woman who won last year's Q-school.
The 90-hole tournament will cut to the low 70 players and ties after the fourth round. Twenty-four players will gain exempt spots on the 2006 LPGA Tour. The next 35 finishers and ties will earn conditional status for 2006.