Former SA Labor minister Leon Bignell has claimed victory in his battle for Mawson — the final Lower House seat in contention in the wake of his party's electoral defeat.

Mr Bignell was widely tipped to lose to Liberal candidate Andy Gilfillan because of an electoral boundary redistribution affecting the seat south of Adelaide, but has held on by just over 100 votes.

The ABC election computer called the result yesterday, but Mr Bignell was reluctant to claim victory until after a final count.

He has since expressed "a great sense of relief" after his long wait for a result from last Saturday's election, which was won by the Liberals, ending 16 years of Labor government.

"It's either 113 or 115 or perhaps 117 votes," he said.

"I think they kept getting a different result every time they counted but the Electoral Commission has declared me the winner in the seat of Mawson."

During the campaign, the colour of some of Mr Bignell's election posters raised the ire of his Liberal opponents.

Liberal leader, now Premier, Steven Marshall said the use of the colour blue instead of the traditional Labor red was a ploy intended to trick voters.

On Sunday, the commission carried out a final distribution of preferences for the seat of Mawson, with Mr Bignell later paying tribute to his opponent, Mr Gilfillan.

"He worked really hard and I guess unfortunately in these situations there has to be a winner and a loser," he said.

"Andy's missed out this time round, not by much."

Mr Bignell was elected to Parliament in the so-called Rannslide, when Premier Mike Rann was returned in 2006.

The result leaves Labor with 19 MPs in the House of Assembly and the Liberals with 25. There are also three independents.