“I thought we might be still counting on Tuesday or Wednesday,” she admits.

Byelections are rarely very memorable, but Ms Kearney’s against-the-odds win for Labor over the Greens last Saturday seems destined to be talked about for a long time, by both parties.

Perhaps the greatest surprise in a campaign full of twists and turns was the margin of victory for the former ACTU president. The winner was locked in by 8.45pm on Saturday, with the Greens well beaten despite being widely fancied by punters and pundits.

The 46-to-54 two-party preferred margin was not what Ms Kearney expected.

“I honestly did not expect the turnout we got in the end," she said. “More than anything, it was a surprise.”

Instead of counting votes on Wednesday, Ms Kearney was being briefed by Department of Finance bureaucrats on her responsibilities as a new MP.

But after the euphoria of a victory that gave a massive boost to Labor’s hopes in similarly tight inner-city contests against the Greens comes the reality that Batman will have to be fought for again, next year at the latest, against what remains a very evenly matched opponent.

A former ACTU president elected to Federal Parliament raises expectations among political people, but Ms Kearney told Fairfax Media this week that her first priority is holding on to her seat.

“I haven’t got frontbench ambitions; I have to consolidate myself in this seat,'' she said. ''That’s not being corny, that’s hard and fast politics.

“I’ve heard on the grapevine that people are saying, ‘We’re watching Ged.'

“So I just want to work hard with the community and show them that I am the type of person who lives up to what I’ve promised and, well, consolidate.

“I want people to feel that I’m worth voting for again.”

Labor’s slick and well-resourced Batman campaign relied heavily on its candidate's natural warmth and followed a deliberate strategy not to engage in the political rough stuff or “dirty up” their Greens opponents.

But it wasn’t always easy to keep smiling, especially when Greens leader Richard Di Natale launched his last-minute pitch to ask conservative voters in the seat, worried about Labor’s new franking dividend imputation policy, to vote Green.

“I just thought it was a bit disingenuous, to be honest, because they voted with the government to cut pensions and it’s the kind of policy the Greens should support,” Ms Kearney said.

“It made me cranky.”

Ms Kearney's campaign also had a decent dose of luck with relatively few hiccups or own goals, while her opponent Alex Bhathal was dogged by leaks and sabotage as the Greens' local Darebin branch chose the worst possible time to tear itself apart.

But Labor's hero says there were days when things did not look so rosy for her campaign, which was managed by ALP assistant national secretary Paul Erickson.

"I always thought there was a chance [of winning]," Ms Kearney said.

“But there was a couple of times there where I rang up poor Paul Erickson and said, ‘Oh no, this is terrible. I don’t think we’re going to do it.'

“But it never stayed down for long.

“I’m one of these people who can live in the moment. I can actually turn my mind from day to day and if this day was good, then that’s OK ... and we had a lot of good days."