Independent Kate Chaney has won the previously safe blue-ribbon seat of Curtin, in Perth's wealthy western suburbs, from one-term Liberal MP Celia Hammond.
Ms Hammond had held the seat on a safe margin of 13.9 per cent but could not hold back a massive swing towards Ms Chaney, who campaigned on the issues of climate change, integrity in politics and inclusive communities.
Ms Chaney promised to hold the Albanese government to account on these issues.
Ms Chaney today claimed victory, saying she was very proud to stand as the first female West Australian independent elected to the House of Representatives.
"It really is a huge honour to represent my community," she said
Ms Chaney's grandfather and uncle were both federal Liberal ministers, but she had become frustrated with the country's leaders on both sides of politics.
Result changes agenda: Chaney
She said it was always going to be a close result.
"I think that a nearly 15 per cent swing against the Liberal Party sends a really strong message that communities want to see politics done differently," she said.
"And it's a really exciting time in Australian politics. A huge thanks to not only my team but my family as well, for all the support they have given me over this incredible four-month experience."
Late on Thursday Ms Chaney led 51.03 per cent to 48.97 per cent on a two-party preferred basis, as postal votes continued to be counted.
In a reference to other so-called teal independent candidates, Ms Chaney said her campaign and other campaigns like it around the country had changed the focus of politics.
"And put issues on the agenda like climate action and integrity and the treatment of women and the Uluru statement," she said.
"I do want to acknowledge that today is Sorry Day and acknowledge the Stolen Generation on this day.
"And Anthony Albanese's victory speech indicated he has a willingness to act on these issues, and now it's my job to work closely with government, and the expanded crossbench and the opposition to hold government to account on delivering on these issues."
For generations, Curtin was the jewel in the federal Liberals' WA crown, covering 98 square kilometres of Perth's most affluent coastal and riverside suburbs, including its so-called "golden triangle".
Former foreign minister Julie Bishop won the seat in 1998 for the Liberal party and held it for 21 years until her retirement from politics in 2019.
Ms Bishop handed the reins to Ms Hammond, who comfortably won the seat at the 2019 election.
'Community reclaiming politics'
Ms Chaney promised the people who did not vote for her that she would consult broadly with the community on policy issues "to ensure I am voting in accordance with the values of Curtin".
"Do hold me to account on delivering on that," she said.
Responding to Liberal MP Tim Smith's comment that teal independents were "loud, entitled and rich", Ms Chaney said it would be a difficult time for the Liberal party after losing "their traditional core".
"I'm not surprised there's some high emotion about it," she said.
She also believed there would be a change in the way government worked, with indications the Albanese government wanted to be more consultative.
Proposed legislation on an integrity commission put forward by independent MP Helen Haines was " a really good start" which she would "happily support".
"I think the expanded crossbench is the really exciting thing about this government," she said.
"I think it is community reclaiming politics."
Ms Chaney also paid tribute to Ms Hammond for representing Curtin during the difficult pandemic period.
Celia Hammond concedes defeat
Earlier Ms Hammond said in a statement it had become clear Ms Chaney would win.
She congratulated Ms Chaney on her election and wished her the best.
"It has been a privilege and honour to have served for the last three years as the representative for the people of Curtin in the Federal parliament," Ms Hammond said in the statement.
Ms Hammond, the former Notre Dame University vice-chancellor, thanked the Liberal Party, her staff and the people of Curtin for the chance to represent them.
Ms Chaney's victory means the Liberals lost five seats in Western Australia at the federal election.
Women's voices important: Albanese
Prime Minister Anthony Albanese congratulated Ms Chaney on her victory and reiterated the importance of female voices in parliament.
"People need to be heard," he told Nine Radio.
"And people who have been voted for and elected like Kate Chaney, as well as members of the opposition, deserve the right to be heard.
"I congratulate Kate on her election. It's a significant achievement to win a seat like Curtin."