Shanshan Feng posted a two-under 70 to double her advantage at the halfway stage of the US Women’s Open in New Jersey.
With President Donald Trump watching on at Trump National, Feng mixed three birdies with a sole blemish to move two strokes clear of a three-way tie for second.
Korea’s Amy Yang is joined by compatriots Jeongeun Lee and amateur Hye Jun Choi on six under, with Seon Woo Bae in fifth following a second-round 69.
World No 1 So Yeon Ryu sits in the group tied-sixth and on four under, while Charley Hull leads the British interest after a long-range birdie at the last moved her within six of the lead.
Holding a one-shot lead after a weather-affected first round, Feng saw a gain at the sixth cancelled out with a blemish at the 10th before birdieing her next two holes to set the target.
“I played probably the first nine holes in the rain, but my phone told me it was going to rain all afternoon and I was prepared,” Feng said. “I really didn’t pay attention to the weather and just concentrated on every shot.”
Choi threatened the lead when she reached the turn in 34 and then fired a hat-trick of birdies from the first, only for the 17-year-old to bogey two of her final three holes.
Lydia Ko and Brooke Henderson lie in the group on three under and Catriona Matthew joins Lexi Thompson seven off the pace, as world No 2 Ariya Jutanugarn missed the cut.