Australia defeated Sri Lanka by 20 runs in its first Twenty20 match since capturing the T20 World Cup last November in the United Arab Emirates.
Sri Lanka finished with 122 runs for eight wickets on Friday after Australia scored 149-9 after Sri Lanka captain Dasun Shanaka won the toss and sent the home side in to bat.
Sri Lanka's required run total was adjusted under the Duckworth-Lewis system due to a short rain delay that reduced the visitors' overs to 19.
Josh Hazlewood led Australia with four wickets for 12 runs in his four overs while Adam Zampa took 3-18.
The teams play again on Sunday at the SCG in the second game of the five-match series.
In the Australian innings, Ben McDermott carried his impressive Big Bash form into the first T20 international to help the hosts set Sri Lanka a moderate initial target of 150, later reduced to 143 due to the rain delay.
McDermott recorded his first half-century at international level with 53 from 41 balls before falling lbw to Chamika Karunaratne.
McDermott, who replaced the rested David Warner as captain Aaron Finch's opening partner, was restricted in the opening stages but began to find his groove.
Finch went cheaply but McDermott, who averaged 48 in the T20 Big Bash, built a hard-fought 50-run partnership with Josh Inglis (23).
“It was an unbelievable performance from our bowlers," Finch said.
Sri Lanka has not beaten Australia in T20 cricket since 2017.