The first Asian clean sweep of the women's golf majors in one season has been on the cards for some time and looks likely to be completed at Hoylake on Sunday.
South Korea's Jiyai Shin, winner at Sunningdale in 2008, took charge of the Ricoh British Open again in a second round which was restarted after Friday morning's 60mph gusts made the Royal Liverpool course unplayable.
The 24-year-old former world number one's brilliant eight-under-par 64, the best score of the week by four shots, swept her into a five-shot lead.
A 36-hole marathon is still to come on the final day but even if she loses to her closest overnight challenger, the 'Eastern Slam' will still go into the record books. Standing in second place is her compatriot Inbee Park.
Two more Koreans, Sun Young Yoo and Na Yeon Choi, captured the Kraft Nabisco and US Women's Open titles earlier in the year, while China's Shanshan Feng won the LPGA Championship.
Shin, who flew to Britain after winning a nine-hole play-off against American Paula Creamer in Virginia on Monday, said of her round: "I think it's the best round I've ever played.
"I had nine under there (in Virginia), but it was soft greens and fairways and easy to hit it aggressive. This is a totally different golf course.
"My goal was one under every single day, so eight under - wow. I can't believe it."
Taiwanese world number one Yani Tseng will not consider herself out of it yet, but her hopes of an unprecedented third successive victory in the event nosedived when she double-bogeyed the 17th. After a second 72 in a row, she has nine strokes to make up.
Japan's Mika Miyazato and Australian Karrie Webb share third place on three under, while the only European below par is 41-year-old Swede Carin Koch, two strokes further back after a 71.