Konta, who reached the fourth round of the US Open last year, enhanced her growing reputation further by thrashing the eighth-seed, dropping just six games in a 79-minute rout on Rod Laver Arena.
It solidifies her position as Britain’s number one and, although coming against an out-of-sorts Williams, the win was built on a mixture of devastating groundstrokes and impressive defence.
After getting through this tough opening draw against her idol she will now face either Carina Witthoeft or Saisai Zheng, both unseeded, in the second round and will fancy her chances of making it into the third round at least.
Konta, born in Sydney, was making her first appearance in Melbourne but did not look out of place as she got stuck into Williams early on, absorbing the seven-time grand slam winner’s power and manoeuvring her around the court superbly.
She was taking a liking to Williams’ serve as well and got her first break in the third game to lead 2-1 and then was grateful for a raft of unforced errors as she got a second break to lead 5-2.
The second break proved vital as Konta wasted a set point as her serve faltered for the first time, allowing Williams to give herself hope after then holding at 5-4.
There were no such worries in Konta’s second attempt at serving for the set, though, as she held to love, delivering it with her third ace.
She wrapped it up in 41 minutes and with Williams producing a costly 14 unforced errors.
The second set was a virtual walkover as Konta broke her opponent’s spirit with some scintillating tennis.
She was licking her lips every time she came up against Willams’ serve, breaking three times in a row and holding twice to race into a virtually unassailable 5-0 lead where she dropped just seven points.
Konta’s copybook was blotted as Williams put up some resistance to break when her opponent was serving for the match, but as with the first set Konta came good at the second attempt.
She nervously had to fight off two break points, but eventually held when Williams sent a 19th unforced error into the net to seal a famous victory.
And it was one the world number 47 did not see coming, having lost in the first round at her two warm-up tournaments.
“When the draw came out and I saw who I was playing I just thought that I hoped to stay out there more than an hour,” she said.
“Right now it is still very much a blur.
“I played two previous tournaments and I didn’t quite get the results I wanted but I have a very strong belief in the way I want to play out there and the way I way I want to be thinking, so I keep trying every day.
“Sometimes you win, sometimes you lose and today I won.”