First-round leader Mirim Lee shot a 5-under-par 67 on Friday and holds a two-shot lead after two rounds of the JTBC Founders Cup LPGA tournament in Phoenix, Ariz.
Lee had three birdies and an eagle on the back nine on the Wildfire Golf Club course, helping her to a two-round total of 13-under-par 131.
"I played a little boring on the front nine, so I went more aggressive on the back nine," Lee said through a translator. "It worked well so now I plan on being aggressive the rest of the week."
Although Lee leads, the story of the tournament may be 16-year-old Lydia Ko, who shot a 6-under 66 on Friday that moved her up to second place, two strokes off the lead.
Ko eagled the 15th hole and went 6-under par in a six-hole span from the 12th through 17th holes.
"I was really surprised," Ko said of discovering she was just two shots off the lead. "I just gave myself more opportunities on the back nine. I played much better this nine yesterday, so I kind of thought, you know, you can make some more birdies and get closer to the leader."
As a result, rookies Lee and Ko will be paired for Saturday's third round.
"I've never really met her before, so should be good tomorrow to meet her and get to know another rookie," Ko said.
Ko is one shot ahead of third-place Sun Young Yoo, who tied for the best round of the day, a 7-under-par 65 that included seven birdies and no bogeys.
Yoo's two-day total of 10-under 134 leaves her one stroke ahead of four players tied at 9-under - Chella Choi, Jessica Korda, So Yeon Ryu and Inbee Park.
Morgan Pressel, who started Thursday's first round on fire by shooting 9-under par for the first 11 holes before finishing that round with a 65, shot an even-par 72 on Friday and dropped six strokes off the lead.
Michelle Wie made a run early in the second round. She held the lead briefly in the morning after four straight birdies moved her to 10-under-par.
However, Wie, who started on the back nine, bogeyed the fifth and the ninth, which was her finishing hole, to drop her into a tie for eighth at 8-under.