Just hours after polling booths closed, the Liberal Party claimed victory in the Bragg by-election – but the "jewel in the Liberal's crown" is now a marginal seat.
On a two-party preferred basis, there are less than two percentage points separating Liberal candidate Jack Batty from Labor's Alice Rolls, with thousands more postal and pre-poll votes to be counted from Monday.
Despite that, Mr Batty declared victory while addressing the Liberal Party faithful at Feathers Hotel in Burnside on Saturday night.
"We're confident we've won the by-election of Bragg tonight," he said.
Ms Rolls said she had spoken to Mr Batty on Sunday morning and while it was too early to formally concede, "it looks like he's going to get over the line by a whisker".
Ms Rolls described the close result in the previously safe Liberal seat as "outstanding" and thanked the residents of Bragg for their support.
"What they showed yesterday was they don't want to be taken for granted," she said.
Premier Peter Malinauskas said Bragg was now a marginal seat following yesterday's vote.
"And that, in no small part, is a product of Alice's really hard work over the last month and the outstanding person that she is," he said.
Labor, Greens build on voter discontent
Former deputy premier Vickie Chapman won the seat of Bragg at the March state election with a margin of 8.2 per cent.
Still, the Liberal Party suffered a 7.6 per cent swing against it.
The by-election results so far have seen a further swing against the Liberal Party, with the Greens increasing their primary vote from 12 per cent at the March state election, to almost 18 per cent.
That may drop once all pre-poll and postal votes are counted on Monday.
Greens candidate James Bastiras went into the race hoping to build upon the "green wave" that swept across SA during the state and federal elections, which clearly showed voter concern with environmental issues.
"We are the party that stands for strong action on climate change," he said.
"[That includes] the protection of our tree canopies, our creeks, and we are also arguing for more school placements for our young primary school kids."
Ms Rolls went into the by-election hoping to capitalise on voter discontent with the Liberal Party – seen in both the state and federal elections – and now again with some voters expressing annoyance at Ms Chapman’s resignation.
"At a cost of almost three-quarters of a million dollars … they are angry about that. They are also angry that they feel like they have been taken for granted in this seat."
Final results could take days
According to the Electoral Commission of South Australia (ECSA), more than 4,500 early votes have been cast in the by-election with a similar amount of postal vote applications sent out.
"With this number of declaration votes, the results for the Bragg by-election may not be known until next week, after the declaration votes are counted."