This will undoubtedly be the best medal of them all for the world number four, who was untroubled until the final, but dug deep to overcome a stunning comeback from Perry.
King was a delighted, and relieved, figure after the match.
"I definitely did it the hard way, and that's all credit to my opponent – she never went away, she just kept coming back.
"My goal today was to go out there and leave everything on the court, and that's what we both did – it's nice to have come out on top."
For King, her success saw her go two steps further than in 2014, when Nicol David defeated her in the semifinals.
It is a victory continues King's rise up the world squash ranks, as she held off an agitated Perry in a clash with several twists.
From the start, the match was a battle, with the opening game being a relative marathon in squash terms. It was a high quality opening with both players hitting some sumptuous angled drop shots, before trading some fortunate moments as the game went into a tiebreaker.
Perry missed two gilt-edged chances to win the game, and ending up ruing her mistakes as King charged back to win it, 16-14.
The clash had a touch of bizarre familiarity to a rugby league game – Perry was constantly complaining about King running obstruction, while the umpire's response was for Perry to "play the ball".
In between the complaints though, there was some excellent squash being played, with King in particular responding well to every query Perry threw the umpire's way, playing some nifty shots to build a slight edge.
King says her composure under pressure was the key to victory.
"That's something this year that has improved the most for me – my composure. Even when things get tight I'm able to keep focused on playing point by point. When you're playing squash like that, it just instinctively happens."
Some deft touches in the second game gave King the edge, 11-8, for 2-0 lead, but the tide turned in the third game, with Perry overcoming an injury scare to fight back.
Chasing a drop shot, the world number eight stumbled and crashed into the wall, requiring an injury timeout; a "self-inflicted" injury timeout, as the umpire wryly noted.
After the break, she managed to regroup and take the third game 11-6, and continued her comeback in the fourth.
Up 9-8, King wanted to appeal a pivotal point, but got no such luck from the umpire, with Perry rebounding to save two match points, then reeling off two more points to send the clash to a deciding game.
Just as it looked like King was running out of steam, she refound her best form, hitting some lovely shots as she just managed to claim a captivating victory. She got off to a perfect 5-0 start in the final game, but Perry – ever the fighter – crawled her way back to make it 8-8.
There, Perry had a brain explosion, picking up a ball when expecting a let. She didn't get it, lost the point, and King clung on to clinch a historic gold.
More medals could be on the way, with King and Coll both back in action in their respective doubles tomorrow, before joining forces for the mixed doubles.
