Former Labor minister Leon Bignell has claimed victory in his seat of Mawson, the last to be decided in the South Australian election.
The final count on Sunday left Mr Bignell 115 votes ahead after preferences despite trailing his Liberal opponent Andy Gilfillan on the primary count.
He pledged to continue to work hard for his constituents whether they voted for him or not.
"I will be doing everything I can to help you and your family, community groups, businesses and schools," he said in a Facebook post.
"It is a huge responsibility to represent my 24,000 bosses. I won't let you down."
He also paid tribute to his Liberal opponent, who he said gave his "absolute all".
"I had never seen a rival make more phone calls or knock on more doors than you did," Mr Bignell said.
"What I liked most was we could have a joke, we could say nice things about each other and we could have a beer together.
"There was never a cross word between us or our teams."
Mr Gilfillan described the election count as a "bit of a nail-biter".
"Although I am now the one with highest primary vote, I have not won," he said.
Mr Bignell's win will leave Labor with 19 seats in parliament's 47-seat House of Assembly while the new Liberal government will control 25 and there will be three independents.
With more than one million ballots now counted across the state, the Liberals received 38 per cent of the primary vote compared to 32.8 per cent for Labor.
Nick Xenophon's SA-BEST party finished with 14.1 per cent and unable to win a single lower house seat.
The SA Electoral Commission will start to officially declare results from Monday, though it will take longer to finalise the count in the upper house where the Liberals and Labor are likely to each win four of the 11 seats up for grabs with SA-BEST taking two and the final seat going to the Greens.
