Ko is probably the most even keeled golfer I've seen. "I just tried to enjoy it out there". That's why I am just more comfortable, don't even think about the winning, I just enjoy the play. "That's why it happened today". She was also Rookie of the Year on the Korean LPGA Tour in 2014 and won three times on that circuit last year.
Henderson, 18, was grouped with Ko in a battle of teen titans in the first two rounds.
Cristie Kerr and Minjee Lee, who both shot 5-under in round one, were among the other leaders playing in the afternoon.
"I didn't start off very well, missing the fairway on one", Ko told reporters after beginning her round with a bogey and ending it with a four-foot putt for birdie at the last. But hitting three, she managed to save par by laying up perfectly in front of the green, hitting her approach past the hole but on line, then sinking a 15-foot downhill putt from the back edge.
While contending in a major is a mostly new experience for Park, Ko is an old hat at it at the age of 19.
Ko came from behind this year to win ANA Inspiration and last year to win the Evian Championship, her two major titles.
"I look a lot calmer than what goes on in the inside". "... I think nerves are good because it means you're excited".
Sharp, meanwhile, has her eyes on a top-10 finish, which would be her best in a major championship.
She carded a two-over 74 to join Ji, who signed for a 70, on 210. Thirty-seven LPGA events have been won by teenagers, with Ko accounting for 13. Defending champion: In Gee Chun. The top 60 on the leaderboard, plus ties, make the cut, as well as any golfer within 10 strokes of the lead.
Wes Short Jr., and Monday qualifier Neal Lancaster also shot 66 and were tied for fourth at 9 under. Sharing in Stanford's celebration were Sandra Gal, left, and Michelle Wie.
Behind us were those following Sung Hyun Park, who had the two-day lead at 8-under.
Paul Goydos shot a six-under 66 to forge a tie for the lead with John Riegger after two rounds of the Dick's Sporting Goods Open at Endicott, N.Y.
"I expect her to play well, you know". It resulted in a double-bogey seven, dropping back to seven-under par and giving Ko a sniff of the lead. It was sitting in a hole and I didn't play it well. "But because the days are going on and the weather has been really nice, I think it is a lot firmer than what it would have been on a Tuesday morning. I want my mom's cooking, and that's it. And that's what I look to do".
"But my birdie on three kind of turned the round around and making the string of (four consecutive) birdies definitely helped".
Mickelson made the cut, which was at 2 over, after recovering from two bogeys on his first four holes that put him on 6 over for the tournament. On the par-5 16th - his seventh hole - the five-time major champion ran a 2-iron to about 4 feet and made eagle. There was our group heading up with us following the three-some of Ko, Danielle Kang and Haru Nomura.
Mickelson said his putting was better Friday after taking time to make adjustments to the slower greens than he is used to playing on the PGA Tour. So I said, oh, I over read it again, huh?
So what kind of golf course is this, what kind of championship is this, who do you trust?