A super round of 66 from In Gee Chun propelled her to the top of the leaderboard at the AIG Women’s Open, with Ashleigh Buhai and Madelene Sagstrom just a shot back after a frenzied second day at Muirfield.
Earlier on Friday, it had seemed that four-under-par may be enough for a share of the lead but Chun had other ideas, shooting four birdies on the back nine, three of which came on the toughest stretch of holes, to make it to eight-under.
Buhai's surge came much earlier on the course, as she emerged from the first six holes with three birdies and an eagle on her way to a 65.
Two stars used to competing at the business end of this event put themselves into contention too. Last year’s runner-up Madelene Sagstrom finished level with Buhai on seven-under, matching Buhai's 65, while 2015 champion Inbee Park ended the day a shot further back in fourth.
At one stage there was an eight-way tie at the top and 32 players within three shots of the lead, before Buhai and Chun raced clear of the chasing pack.
Chun began her round in relatively quiet fashion, with a bogey at the sixth offsetting a birdie just a hole before. But then a sensational approach from the edge of the rough on the ninth set up another gain and seemed to provide the spark for a stunning back nine.
The birdies came at a frequent rate thereafter, at 11, 13, 15 and 17. Luck played its part along the way too, with the ball dropping into the cup after hanging on the edge for what felt like an eternity at the par-3 13th.
A gritty up and down from distance at 18 then saved par and that would prove crucial, as Buhai later faltered at the final hole.
However, Buhai's troubles at the last did little to detract from what was a brilliant display, particularly before the turn, as she went out in an astonishing 30.
Buhai might even look at that bogey on the 18th fondly, given the position she found herself in. A chunked approach came up way short in a cross bunker and from there she flew the green before sinking a seven-footer for par.
The South African is hoping to follow the path laid out by Ernie Els, whose second round at The 131st Open was his best of the week en route to Muirfield glory.
She is joined at seven-under by Sagstrom, who did her chances of going one better than last year no harm at all with a masterful 65.
Also in the mix is Inbee, who produced arguably the putt of the round at the 14th with a monster effort for birdie, one of five for the seven-time major winner. Hannah Green and Miyuu Yamashita are within touching distance too, at five-under-par.
The star of the opening round, Hinako Shibuno, struggled to replicate her day-one showing. While she carded a 73 to be one of four players at four-under, Jessica Korda slipped further back with a 74 and is now six shots off the pace.
Louise Duncan remains the lowest-scoring Brit but she too found the going tougher on Friday, carding 73 as she dropped to two-over-par.
Duncan will pass the title of Smyth Salver winner onto Rose Zhang, the only amateur to make the cut. The 19-year-old and number one ranked amateur in the world is even-par after 36 holes and can be mightily pleased with her efforts.
Elsewhere, Anna Nordqvist became the third consecutive AIG Women’s Open champion to miss the cut as she finished four-over-par.
She was not the only star name to miss out, however, with world number one Jin Young Ko also among those departing at the halfway stage.