Angel Yin of the United States rocketed into a two-way share of the lead at the LPGA Shanghai after firing a seven-under-par 65 in Saturday's third round.
Yin and overnight leader Maja Stark of Sweden were joint top of the leaderboard on 12-under with one round to play in the $2.1 million event at Qizhong Garden Golf Club.
The duo was a shot clear of Thailand's Pavarisa Yoktuan.
World number one Lilia Vu of the United States, Lee Mi-hyang of South Korea and another Thai, Ariya Jutanugarn, were another shot back on 10-under.
Germany's Esther Henseleit and home player Liu Yu were tied for seventh on nine-under.
Danielle Kang, the American who won the two previous editions in Shanghai in 2018 and 2019, fell from second overnight into a share of ninth with a one-over 73 and was four shots off the pace.
Yin carded the lowest round of the day in hazy conditions, starting with a bogey but then racking up eight birdies to surge into serious title contention.
The 25-year-old, who has shot up the rankings this year to 35 in the world, is chasing a first LPGA victory.
"I yelled at my caddie, I actually did," Yin, who started the day 14th, said of her reaction to her bogey on the first hole.
"I wasn't yelling at him, but I was like, 'I think our communication is not great, we're going to work on it.'
"Then we just did it."
Stark, who has been at the top of the leaderboard since the opening round, had four birdies and two bogeys for a third-round 70.
She admitted to some nerves as she contemplates a second victory on the LPGA Tour.
"It would mean a lot to win it just to prove to myself that I can actually do it when we have a lot of top players here," she said.
The Shanghai LPGA is the first international golf event in China since the Covid pandemic.