South Korea's Ryu Hae-ran shot a sizzling second round 10-under 62 to open up a six stroke lead at the LPGA's FM Championship at Norton, Massachusetts on Friday.
The 23-year-old caught fire on the front nine making four straight birdies from the fourth hole onwards at TPC Boston.
She produced another four birdie streak from the 14th hole as she took command of the leaderboard as she searches for her second win on the LPGA Tour.
"Just an amazing day because my shots, everything next to the hole and my putts, everything went in the hole," said Ryu, who bettered her previous career-low 18-hole score of 64.
The South Korean, in her second year on the LPGA Tour, said she hadn't expected to be able to go so low in her scoring on this course but quickly discovered that it was perfect for her game.
"Because the greens are so small and the course condition is really firm this week, but I love that condition because my shots (are more) accurate than other players, so I love this course. These greens are so clear, so I just trusted my strokes and made so many birdies today," she said.
Ryu has delivered five top-5 finishes this season as she looks to add to her win in Arkansas in October.
Three players are in a tie for second at 7-under, six shots back of Ryu – Australian Robyn Choi, American Yealimi Noh and Bianca Pagdanganan of the Philippines.
Pagdanganan shot a bogey-free 6-under 66 with half of her birdies coming on the first three holes.
"It's weird. I feel like I should be happy with a round of 6-under, but starting off really hot I thought that I could keep that going. Once I made the turn, I think the putter just went cold," she said.
"It's fine. Knowing that I could post a good score today definitely helps my confidence. I don't think I made that many long putts for birdie. But I've got two more rounds, so we'll just see how tomorrow goes," she said.