Yukari Baba had a sweeping start to the Masters GC Ladies on Friday, shooting a bogey-free 67 to take sole possession of first place in the ¥123 million event.
Baba birdied the opening hole before adding four more on the back nine at the Masters Golf Club, where the 28-year-old held a one-shot advantage over Izumi Narita.
Ahn Sun Ju, the Japan LPGA money leader seeking victory for the third straight week, stumbled off the blocks as the South Korean carded a 73.
"I didn't think Ahn would be doing this well before the season started," said Baba, who has yet to win this year. "She's clearly on a roll and she's running away with it. The rest of us have to do better and put up a fight."