Williams, the hot favourite to claim the Melbourne Park major for a sixth time, delivered a thundering message that she fully deserves that favouritism with her 6-2 6-1 dismissal of Barty.
Barty, the world No.155, is just starting her first full year on the WTA Tour but has shown enough in her brief career to indicate she has a bright future.
Her most recent match had delivered an impressive win over Slovakian star Daniela Hantuchova, in the Brisbane International late last month.
She had not played since because of a left adductor injury and entered Rod Laver Arena on Monday night with her left thigh strapped.
Despite coming off that injury, Barty had expressed excitement pre-match at the opportunity to take on the world's dominant female player.
But Williams, chasing an 18th grand slam title, didn't take long to assert control, with the enormous power of her serves and groundstrokes having Barty almost constantly on the defensive.
Cheered on by an appreciative crowd, Barty fought gamely to stave off a break point and win the opening game of the match.
But Williams won eight of the next nine points to quickly take the next two games.
While Barty managed another hold of serve to reach 2-3, the American raised her level even higher to win the last three games of the first set and first four of the second.
Barty sheepishly raised her arms and smiled in mock delight, after she won the fifth game of the second set to break a run of seven straight games for the rampaging American.
It was a brief respite for the Australian, who ended last year as the second-youngest player in the world top 200 and made three grand slam doubles finals with partner Casey Dellacqua.
Barty staved off one match point, but couldn't stop Williams the second time as the American clinched the match in 57 minutes to set up a second round meeting with Serbian Vesna Dolonc.
Williams said she had regarded Barty as a dangerous opponent and felt she had a bright future.
"I just think she's so cute and I like her a lot," Williams said.
"She's so young, I'd like to see her do really well.
"I think she has a game to do really well. We'll see."
Barty said Williams had an unbelievable presence on the court, but she had enjoyed the experience despite the result.
"It was just awesome to have the opportunity to play against her tonight," she said.
"I learned a few things. It's going to be a really good experience for me moving forward."