The leg-spinner, so often the scourge of English batters in Ashes clashes, bowled an immaculate line and length, as so often extracting more turn than anyone else, as she took 1-20 off her 10 immaculate overs.
It completely took the steam out of England's attempted mid-innings surge and, aided by three more scalps for the tournament's leading wicket-taker Annabel Sutherland (3-60) and a couple each for spinners Sophie Molineux (2-52) and Ash Gardner (2-39), put the champions in a powerful position.
With captain Alyssa Healy sidelined as a precaution with a "minor calf strain", stand-in Tahlia McGrath won the toss, elected to field first and led her troops with fine tactical aplomb after a tough start when Tammy Beaumont and Amy Jones led off with a half-century partnership in the powerplay.
Sutherland, so impressive with the ball all tournament, made the breakthrough with her outswinger clipping the top of Jones's off-stump while Molineux made another key intervention by trapping the dangerous Heather Knight lbw on the backfoot.
King was brilliant from the start and made the key breakthrough by tempting England captain Nat Sciver-Brunt to slice and sky one into the safe hands of Sutherland at mid-off.
"She's a special player, she's a big wicket. I was happy to see the back of her, we know how damaging she can be. She's got us many times in the past before," said King of Sciver-Brunt's dismissal.
"I kept it really simple, kept the stumps in play as much as possible and tried to extract as much spin as I can."
It was a combination that proved too much for the English batters to deal with.
Beaumont, their mainstay, battled to a fine 78 off 105 balls, but trying to push on amid King's strangulation of England's middle-order, it was Sutherland who got her caught expertly on the boundary by an off-balance Georgia Voll, who had to throw the ball up and re-catch it to avoid giving away a six.
Alice Capsey (38 off 32) and Charlie Dean (26 off 27) provided a bit of late impetus for England as they sought to earn a psychological blow with both sides having already qualified for the semi-finals.
