A 6-2 6-2 victory for Swiatek was the perfect way for the Polish 19-year-old to complete a successful week in which she did not drop a set in five matches, losing only 22 games.
Swiatek achieved her shock Roland Garros triumph in the same way, sweeping through the Paris draw untroubled with a string of straight-sets wins.
She appears set to climb into the world's top 10 before long, with this week's work enough for her to jump three places to No.15 in the WTA rankings.
Leading the winners count 22-9 reflected Swiatek's dominance of a match that she closed out in one hour and six minutes.
Swiatek reached the Australian Open fourth round earlier in February, with her run in Melbourne halted when Simona Halep avenged her French Open defeat to the teenager.
After sinking Bencic's Adelaide title hopes, Swiatek expressed gratitude to tournament organisers and the Australian government for allowing tennis stars into the country, which has imposed tight restrictions on travel during the pandemic.
Swiatek said in an on-court speech: "I want to thank everybody who made this whole swing possible.
"It's been amazing playing here in Australia and I love to play here. Also, the government, thank you for letting us play and thank you for the opportunity."