The woman who defeated Tony Abbott in Warringah says her grassroots movement has proven there's "no such thing as a safe seat in Australia".
Zali Steggall, an Olympic skier turned barrister, defeated the former prime minister in the northern beaches Sydney seat in a result that Labor labelled a "slaughter".
"This is a win for moderates with a heart," Ms Steggall said during her victory speech on Saturday night.
"Tonight Warringah has definitely voted for the future. Warringah - we have a new beginning for our environment."
Ms Steggall vowed to be a "climate leader" who would hold the government to account when it came to tackling global warming.
"I will push for real action, so our children and generations to come can enjoy the environment and our beautiful beaches, and our beautiful country, the way we enjoy it," she said.
Ms Steggall paid tribute to Mr Abbott as a dedicated and long-serving member saying "I wish him well".
She concluded: "We have shown what a grassroots movement can do. There is no such thing as a safe seat."
With just over 50 per cent of the ballots counted at 9.30pm, Ms Steggall had 59 per cent of the two-party preferred vote, compared with Mr Abbott on 41 per cent.
Mr Abbott said he was "disappointed" to have lost his seat but argued the good news was the coalition could retain power in Canberra.
"It's disappointing for us here in Warringah but what matters is what's best for the country," Mr Abbott said when conceding.
"What's best for the country is not so much who wins or loses Warringah but who forms, or does not form, a government in Canberra."
Mr Abbott told supporters at the Manly Leagues Club: "I'd rather be a loser than a quitter."
He later told Sky News: "At least I didn't lose the seat as PM."
His former deputy, Julie Bishop, described the result as "sad" but noted the former PM didn't match up with his constituents on climate change and same-sex marriage.
"The Liberal Party will have to reassess its position on climate change," she told Nine News.
"It will have to end the uncertainty."
Labor frontbencher Anthony Albanese told Nine News "this is a slaughter".
"It's probably a good thing for the Liberal Party that Tony Abbott is not in the caucus room," he said.
Media were locked out of the former prime minister's election night function and told they'd only be briefly allowed in to record his speech.
Ms Steggall was treated like a rockstar at her reception at the Novotel hotel in Manly.