The 33-year-old upset Bolivian 25th seed Hugo Dellien 6-3 6-6 to lead the Australian charge on day one of action at Melbourne Park.
Olivia Gadecki was also among the locals, the 23-year-old Queenslander setting up a second-round match against former world No.3 Sloane Stephens.
Other Australians to bank first round wins included Tina Smith, Lizette Cabrera and Dane Sweeney, who overcame Italian 26th seed Andrea Pellegrino 6-2 4-6 6-3.
Tomic, who last played in the Open in 2021 when he reached the second round, looked fit and focused in his Monday afternoon match, where he was well-supported by vocal Australian fans.
Ranked some 50 places lower than world No.138 Dellien, Tomic broke to lead 3-1 with six aces helping him comfortably take the first set.
He went ahead 4-2 in the second before wrapping up the match in 72 minutes.
Tomic will next face British youngster Arthur Fery, after the world No.185 overpowered Australian wildcard Edward Winter 6-2 6-4.
Gadecki eased past her Dutch opponent Arantxa Rus 6-2 6-4 and will next face Stephens, who is the only major winner playing in qualifying this week for a spot in the main draw.
The 32-year-old, who won the 2017 US Open and reached the semi-finals of the Australian Open in 2013, was sidelined for seven months last year with a foot injury.
Her WTA ranking dropped outside the top 1000, forcing the American into qualifying for the first time since Wimbledon in 2012.
She opened her account on Monday with a 6-1 7-5 victory over Czechia's Barbora Palicova.
While keeping alive Stephens' hopes of playing in a 14th Australian Open, the win ended a horror 13-match losing streak.
"The last match I won was Wimbledon 2024," Stephens said post-match. "I obviously had a bumpy road on the back of that, then got injured at the beginning of last year and didn't play.
"I'm not going to be like, 'Oh my god, I played so bad'. It was never that. Time passes, things happen and it's unfortunate."
World No.171 Gadecki and Stephens have met three times before with the Australian leading the head-to-head 2-1.
"I played her here two years ago, and then another few times," Stephens said.
"I know her game and I'm familiar with her, and she's a great player and I'm just going to go out and hopefully continue to play good tennis."
20°C