When the five-times victor could barely get her racket to a vicious forehand, it gave the Spaniard three match points, but in keeping with a messy second set, she needed two Hawk-eye challenges to put the beleaguered American out of her misery.
She is the first Spanish woman to win Wimbledon since her coach Conchita Martinez denied Martina Navratilova over three sets in 1994.
And Muguruza was quick to praise her opponent for continuing to scale new heights at the ripe old age of 37. "But she didn't give me much chance to do something". "I'm glad I took mine", Muguruza said.
Ironically, if Williams does win on Saturday, she will be displacing a record already belonging to the family - to her biggest competitor, to her biggest inspiration.
Claire Liu became the first American in 25 years to win the junior title at Wimbledon. Liu is from California and Li is from Pennsylvania. The last all-American final was in 1979 when Mary Lou Piatek beat Alysia Moulton.
The occasion didn't daunt Muguruza, and the IBM SlamTracker showed Williams' 10 unforced errors in the final six games dwarfed the winner's minuscule tally of one.
"It will be an incredible opportunity to be next to the wonderful players that are in the final".
Longevity, battling odds, strength of character, sheer bloody-mindedness - all hallmarks of a champion, which the elder of the Williams sisters has been, despite having 16 lesser Slam titles than the little one.
Twenty years after making her Wimbledon debut, Venus isn't keen to bow out on such a frustrating low note.
It was then her turn to go on the offensive.
But since May she has made the semi-finals on the Rome clay - beating Venus in the last eight in three sets - and on the Birmingham grass.
Konta played quite well, especially early, and finished with more winners, 20 to 19, each greeted by roars from the Centre Court spectators.
Her Wimbledon nightmares were officially banished as the wheels appeared to come off for Venus, Muguruza reeling off nine straight games to claim the title, suppressing any nerves superbly as Williams' fairy tale came to a disappointing end.
With Serena set to miss the rest of the year as she prepares to have her first child, Venus will still be among the favourites to win her eighth Grand Slam title when the US Open gets underway in late August. Not only so, she would also become the oldest women to clinch the title. Now, with her second Grand Slam in as many years, she may be looking to make the leap into tennis's elite.
"She knows how to play, especially Wimbledon finals", Muguruza, the 2015 Wimbledon runner-up and 2016 French Open champion, said about Williams.