Chun has climbed above fellow countrywomen Ko Jin-young and Lee Jeong-eun with 12-under par after a fine third-round display.

The 27-year-old is a three-time winner on the Ladies Professional Golf Association tour but her last victory came in 2018 when she triumphed at the Hana Bank Championship in her home country.

She had considered withdrawing from the World Championship after tweaking a muscle in her neck during the first round but has put together scores of 70, 68 and 66 to rise to top spot.

"I tried to make good focus on the putting green because I have spasm in my neck, so I didn't try to hit hard," said Chun.

"I think it went really well on the putting green, and then I could really bring the greens really well. That's how I made a good score today."

Ko and Lee are one stroke behind Chun in a tie for second at 11 under.

A third-round 69 was Ko’s 14th consecutive round in the 60s, which ties the all-time record she holds with Sweden’s Annika Sörenstam - who leads the International Golf Federation - and South Korea’s Ryu So-yeon.

"It was a tough round because I had a lot of opportunities for birdies in the front nine, but I missed a lot of putts and then missed some chips," said Ko.

"I finished even on the front nine, and I really tried to make three birdies more on the back nine, but it wasn't really helped.

"And I had a little pressure for the record, but I made it."

American Danielle Kang, South Korea’s Amy Yang and Thai teenager Atthaya Thitikul are in joint fourth on nine under, while Canada’s Brooke Henderson is seventh on eight under.