Kim Sei-young produced a superb final hole birdie to maintain her two-shot lead at the halfway stage of the LPGA Tour Championship in Florida on Friday.
The 26-year-old from Seoul fired a 175-yard six-iron to three feet on the 18th hole at Tiburon Golf Club and then drained a simple putt for a five-under-par 67, leaving her at 12 under for the tournament.
Kim, who had shot a seven-under-par 65 to lead by two strokes after Thursday's first round, is chasing her third win of 2019 at this week's LPGA Tour season finale.
After reaching the turn at two under for the round on Friday, Kim suffered a wobble on the 10th when she posted her first bogey of the tournament.
However she recovered well to make birdies in three of her next four holes, before finishing with a flourish on the 18th.
Kim's birdie finish means she has a two-shot buffer heading into the final two rounds as she chases the $1.5 million winner's cheque, the richest prize in women's golf.
Kim admitted the lucrative purse has raised the pressure for the tournament.
"It definitely feels like US Open or British Open," she said. "It feels like a major tournament. But I try not to put myself under any extra pressure."
That relaxed approach will hold the key to her weekend, she added.
"Just focus shot by shot and relax and enjoy, have fun on the course," she said.
Germany's Caroline Masson heads the pursuit of Kim after posting a six-under-par 66 that left her at 10 under after 36 holes.
Masson played flawlessly in a bogey-free round that saw her vault up the leaderboard after making three birdies over the final five holes.
Canadian Brooke Henderson and Nelly Korda of the United States were a shot back on nine under, three off the lead.
Henderson recovered brilliantly after a potentially disastrous double-bogey seven on the par-five first,reaching the turn at level par after birdies on the fourth and sixth holes. Henderson then picked up five more birdies in six holes on the back nine to card a five-under-par 67.
"Not the start I wanted for sure, but I was able to get it back to even after the first nine holes and that was really important," Henderson said.
"I kind of started to get things rolling a little bit...I just seemed to be making a lot of birdies, which is always a lot of fun."
Australia's Su Oh, is alone in fifth place on eight under after a roller coaster round which included seven birdies and two bogeys for a five-under-par 67.
Three players -- China's Liu Yu, Jessica Korda and Lexi Thompson -- are tied for sixth on seven under, five off the lead.
World number one Ko Jin-young's hopes of mounting a challenge appear to have faded however after she could only manage a three-under-par 69.
Ko heads into the weekend on four under for the tournament, eight strokes off the pace.