Henderson has a solid lead over South Korean Hur Mi-Jung (66), Spaniard Carlota Ciganda (64) and Lexi Thompson of the USA in the US$2 million (RM8.55 million) LPGA Tour event. She was tied for 28th a week ago at the Manulife LPGA Classic, but, as she's just one shot back of the lead, she's eager to make a move Sunday.
A three-times victor on the LPGA Tour, Henderson has recorded just one top-five finish this season.
"My irons were really good", the South African player said.
She could have had a bigger lead but ended Friday's round with back-to-back bogeys to reach a 12-under 130 total, setting the Ladies Professional Golf Association tournament's 36-hole record. "And going into the back nine, I just wanted to give myself as many chances as I could".
Henderson won twice previous year, taking the KPMG Women's PGA Championship for her first major, and successfully defending her title in the Cambia Portland Classic.
Putin present to see Russia kick off Confederations Cup
New Zealand is now without a win in four trips to the Confederations Cup , and next plays Mexico on Wednesday in Sochi. The hosts now take on Portugal on Wednesday after Fernando Santos' men have played Mexico in their Group A opener.
She rolled in five straight birdies on Thursday, beginning at the par-three No. 14. "I feel comfortable. I played here past year and I'm excited for the weekend".
Her successor, Thailand's Ariya Jutanugarn (69), was eight off the pace. "It's been a little bit of a rough season so far, you know, not getting the results that I've been looking for".
"I was surprised when I looked at the leaderboard and had a two-shot lead on the 18th green but I'm super happy", Henderson said.
Flooding caused the par five 5th hole to be played as a par three, which saw the course played as a par 69, meaning Thompson's round of 5-under par under was in fact a 64.