Casandra Alexander has taken control of the tournament following an outstanding round at the K Club.
The overnight leader posted a score of 66, which included two eagles to propel her ahead of the competition.
Alexander finished the second day with a total of 129 for the first two rounds.
She sits five shots clear of Sara Kouskova from the Czech Republic and Brianna Navarrosa from the United States.
Kouskova and Navarrosa both posted scores of 68 in their respective rounds.
Alexander's performance began with a bogey on the sixth hole before she secured a birdie on the seventh.
On Friday, she eagled the par-five tenth hole, which served as her opening shot for the day.
She followed that success with consecutive birdies to complete her 66.
A shot was dropped on the thirteenth fairway before a birdie two was recorded on the seventeenth.
Her second eagle of the round came at the third hole of Friday's play.
Canice Screene remains in contention for the home crowd, currently tied for eighth place with four players.
Screene sits five under par after a round of 67 featuring seven birdies and two bogeys.
Aine Donegan fell back to two under par following a disappointing score of 73.
Leona Maguire started the event at four under but dropped to two under after bogeying two of her final three holes.
Maguire's opening round was a 71 before she struggled in the second half of the day.