Leona Maguire remains among the chasing pack at the halfway point of the CME Group Tour Championship where a second successive 69 sees the Cavan woman seven shots adrift of leader Lydia Ko.
The 27-year-old had bogeys at the second and ninth cancelled out by birdies at the third and fourth in a mixed front nine.
However it was the back nine where she made real inroads, closing in 33 with birdies at 11, 14 and 16 to move to six-under par and a tie for seventh place.
Ko however holds a commanding five-shot advantage over Hyo Joo Kim.
The Korean-born New Zealander hit eight birdies and a bogey on her way to a 66, the lowest score of the day after opening with a 65 on Thursday, to sit on 13-under par.
A win would give Ko, 25, a trio of awards: the season-long points race that determines the Rolex Player of the Year, the season-long money title and the Vare Trophy for the season's scoring champion.
Ko entered the week as one of four players mathematically eligible for Player of the Year, along with Minjee Lee of Australia, Brooke Henderson of Canada and Atthaya Thitikul of Thailand. Ko led Lee by a point and would claim the award with a tournament victory.
"I already knew going into the day that it could be tricky, but at the same time because I played really solid in the back nine, I knew that if I did make any mistakes, there were birdieable holes coming in," Ko said.
"That's kind of the goal for me this week is not let one hole or one shot faze me. You know, this is the last tournament of the season. It's my ninth year on tour, so I want to finish the season well and also just want to finish it without any regrets."
Kim recorded four birdies and one bogey on Friday, with consecutive birdies at the par-3 16th and par-5 17th helping her sneak ahead of the pack into sole possession of second.
Tied for third at seven under were Japan's Nasa Hataoka, Sweden's Anna Nordqvist, Nelly Korda and Scotland's Gemma Dryburgh.
Additional reporting: Reuters
