More than one in five voters in the South Australian state election put Pauline Hanson's party first on their ballot paper, according to counts by Sunday afternoon.
That left the anti-immigration party second only to Labor, which returned to power in a landslide victory, and relegated the opposition Liberals to third.
Anthony Albanese didn't directly address the election result on Sunday, but in a speech to Melbourne's Vietnamese community warned against anyone seeking to demonise migrants.
"There are some, including some in political life, who want to turn back the clock to an Australia that is no longer who we are," the PM said.
"We need to call out those people.
"And we need to continue to cherish our diversity as a strength for our nation, which it is."
The election-night boost delivered One Nation two upper-house seats, including for state leader and former federal senator Cory Bernardi, while it was also in the running for as many as four lower-house seats.
Premier Peter Malinauskas will hold at least 32 of the state's 47 lower-house seats, building on Labor's already clear majority.
Senior moderate Liberal and federal frontbencher Anne Ruston, whose party had only secured four state seats with a handful more on a knife's edge, said her colleagues needed to learn "sobering lessons" from the result.
"The Liberal Party has got a lot of work to do to rebuild the trust of Australians," she told Sky News.
"I absolutely believe that we can do that... we just haven't been telling our story very well."
But conservative Liberal senator Alex Antic, a key powerbroker in the South Australian branch, said the result showed the folly of his party pursuing more progressive policies.
"That left-leaning, progressive... message is tailored to inner-city seats," he said.
"That is just simply a failed strategy and it won't work."
He did not rule out jumping ship to One Nation but said he hadn't spoken with Senator Hanson and had no current plans to shift allegiances.
One Nation's result was its best at any poll since the 1998 Queensland election, but some voter surveys have put its federal support higher than the 22 per cent in first preferences so far secured in South Australia.
Speaking on election night, Senator Hanson said the rest of Australia would be watching the state result ahead of a federal by-election in former Liberal leader Sussan Ley's seat of Farrer, and the Victorian state election later in 2026.
The party's sole MP in federal parliament's lower house, Barnaby Joyce, conceded  winning seats could be challenging despite One Nation out-polling the coalition.
Preferences have generally flowed away from the right-wing party in the SA vote.
"That's a good example to the Australian people that if you want the change... you've got to put One Nation first," the Nationals defector said.
