Wentworth is too close to call, with Liberal hopeful Dave Sharma and independent Kerryn Phelps locked in a nail-biting battle for the second time in seven months.
With 73 per cent of the ballots counted, Mr Sharma had 47.2 per cent of first preference votes, while Dr Phelps held 33.1 per cent.
The seat had previously been held by former prime minister Malcolm Turnbull, and many Liberal insiders believed the anger that delivered Dr Phelps victory in last October's by-election had subsided.
She was narrowly behind on the two-party preferred count and told supporters at her official party that she was "waiting to see what happens with the numbers".
Mr Sharma addressed an excited crowd at the Easts Rugby Club in Bellevue Hill, but told them the result was too close to call.
"I'd love to be able to declare a result tonight but I think it is too early for that," he said.
Mr Sharma noted the different sentiment within the community compared to seven months ago.
"There was much less anger, much less hostility, than there was last year," he said.
There were massive swings against the government at last October's by-election, and Dr Phelps increased her primary vote this time but so did Mr Sharma.
Dr Phelps headed into Saturday's vote on a slim margin of less than 2,000 votes.
Campaigning in Australia's most affluent electorate was particularly dirty.
Dr Phelps was targeted with several abusive emails — some included anti-Semitic remarks and claimed she was ineligible to stand while others were homophobic and named her children.
In April, both Dr Phelps and Mr Sharma said campaign posters across the electorate had been stolen.
Less than 24 hours ago Mr Sharma posted on Twitter that his campaign van was broken into at Edgecliff Station.
Dr Phelps campaigned heavily on climate change, pledging to stop the Adani mine in central Queensland as well as other coal projects.
During her time as an MP, Dr Phelps led the passage of the so-called "Medevac" bill, which allowed refugees and asylum seekers in offshore detention to come to Australia for medical care.
Mr Sharma's campaign messaging focused on economic growth.
