The storied Aronimink was always going to provide a tough challenge in its first crack at hosting a women’s major.

And the Philadelphia course was that and more.

It’s just that someone forgot to tell Sei Young Kim.

Kim, the 27-year-old Korean who had previously held the mixed blessing of being the active player with the most LPGA Tour wins without a major crown, was simply unstoppable.

A course and tournament record final-round 63 sealed the KPGM Women’s PGA Championship and her place in history with a 14-under tournament record total that left her a five-stroke winner.

That all-time great and reigning Women’s Australian Open champ Inbee Park was runner-up said plenty.

That Kim was so far into red figures with only seven other women under par says way more.

The Australian contingent each saved their best for last with Hannah Green staying gallant to the bitter end of her title defence with a fine 67 to share 23rd at four over after her opening 79 all but ended her victory hopes three days earlier.

Katherine Kirk mixed three birdies and three bogeys for a 70 that left her in a share of 54th at 10 over, while Minjee Lee had two of each and rallied to finish in a tie for 58th at 11 over a day after an uncustomary 77.

But the day belonged to Kim, who after 24 holes this week had been languishing at three over par.

From that point, she poured in 19 birdies in her final 48 holes on a course that befuddled most.

She joined a growing list of first-time major winners in recent years – her victory means nine of the past 10 major champions had never previously won one. She joins Sophia Popov (Women's British Open) and Mirim Lee (ANA Inspiration) as this year's major champions.

And all with Park chasing furiously.

"I thought 65 will definitely do it," said Park, herself a three-time winner of the event.

"I was thinking maybe like 5-6 under was a good number to post and just see what happens. But obviously Sei Young was just much better than anyone else out there today.

“She was … really untouchable."

Five years later, it was Kim's time to hoist the trophy.

Kim, Park’s fellow 2016 Olympian, was runner-up at the 2015 Women's PGA Championship and tied for second at the Evian Championship in 2018. She’d held the 54-hole lead at the 2015 ANA Inspiration, where she finished in a tie for fourth, but hadn’t saluted at the game’s highest level.

She ensured that today with seven birdies, including four in five holes from the 13th.

"I'm actually really hiding my tears at the moment," she said, standing next to the trophy.

"I won't lie, I did feel the pressure starting last night (but) I really tried to stay composed … during the round and I'm happy that I got it done."