Ged Kearney has thanked voters in Batman for putting their trust in her, after she claimed victory for Labor in the federal Melbourne seat a following a tightly contested by-election battle with the Greens.
The former ACTU boss and Opposition Leader Bill Shorten arrived at Labor's celebration on Saturday to huge cheers and chants of 'Ged, Ged'.
"They said we'd never do it, but we did," Ms Kearney told the pumped up crowd at the Thornbury Theatre.
Thanking Greens candidate Alex Bhathal for a hard fought campaign, she said the win was a victory for "true Labor values".
"Because our campaign spoke to everyone from the ring road to the river," Ms Kearney said.
"We spoke to national progressive values, workers rights, climate change, social justice and a better Australia."
"Labor is on its way to a Shorten government."
Ms Kearney, who does not live in the electorate, also thanked the Batman voters.
"You invited me into your homes, you stopped me in the streets to talk, you sat me down in town halls and told me what for," she said.
"Thank you for putting your trust in me and I won't let you down."
Mr Shorten, who earlier conceded they faced an uphill battle, said Labor was "back" and had proved wrong bookmakers and commentators had written them off in Batman.
Labor would not let voters down, he said.
"Labor hears the lesson and message of Batman," Mr Shorten said.
"More than ever before Labor has to battle the perception that the major parties and political insiders are only in this for themselves."
He congratulated Ms Bhathal and the Greens, saying "at least they turned out".
With the Liberal Party not fielding a candidate, the by-election was test of whether the Greens' march into inner-metropolitan seats would continue or if Labor could successfully appeal to a younger demographic.
Ms Kearney emerged the winner with almost 43 per cent of the primary vote, 54 per cent on a two-party basis, trumping Ms Bhathal who has now lost the seat six times.
The Greens, who had been optimistic about the poll, earlier conceded defeat.
"Obviously, it's not the result that any of us would have wanted," Ms Bhathal told the party faithful gathered at a Preston bar.
"We knew that Labor would throw everything they had at this seat to hold it after 84 years.
"Many people have said over the course of the campaign that regardless of the outcome, we'll have a strong, progressive woman representing us in this seat," she added in a congratulatory nod to Ms Kearney.
Ms Bhathal has run for Batman since 2001, and the Greens had been convinced victory was imminent following the resignation of Labor's Feeney over his dual-citizenship earlier this year.
"It looks like because of the preference from all the hard-right parties, from Cory Bernardi, from Rise Up Australia, that we're just going to fall short tonight," federal Greens leader Richard Di Natale said.
The party staked much of their campaign on opposition to the Adani coal mine in Queensland and tried to trip Labor up over their mixed messages on the project, which Ms Kearney opposes.
The mood was electric at the Labor camp, with supporters wearing red chanting 'solidarity forever' as results poured in, though the count remained neck-in-neck for some time.
Mr Feeney was also at the celebration, but did not wish to comment.
Ms Bhathal, who denied allegations against her of bullying and intimidation during the campaign, said it was too soon to think about considering a seventh run for Batman.
"At the moment I've got no idea. I would have to talk to my husband .... I would have to talk to my boys."
The critical final hours of Saturday's poll were dogged by allegations of dirty tactics.
Labor conducted a last-minute blitz of 10,000 robocalls and 2400 texts, urging senior citizens to vote, after reports some older voters received phone calls telling them they didn't have to.
All up, ten candidates ran for the seat.
Australian Associated Press
