LIBERAL candidate Tony Pasin wore himself out in his bid to fend off Nick Xenophon Team rival James Stacey in the traditionally blue-ribbon seat of Barker.
It has been held by conservatives for a century and spans the state's southeast corner from Mount Gambier to Murray Bridge and the Riverland. 
But last night the seat remained undecided.
Mr Pasin, who cast his vote yesterday afternoon at Melaleuca Park Primary School, Mt Gambier, told the Sunday Mail he was exhausted and although he did not feel confident he remained hopeful.
"It's a long campaign," Mr Pasin said. "We are still waiting for large booths to be determined." The 38-year-old father of two operates a private law firm in Mt Gambier, and has held the seat of Barker since 2013.
Mr Pasin said he always knew a Nick Xenophon Team would be a threat. So he and his team strengthened their efforts, advocating for regional healthcare, jobs, telecommunications and improvements to roads.
Leading the NXT campaign in Barker is James Stacey, a National Party Senate candidate at the 2013 election.
Mr Stacey, who grew up in the farming community of Langhorne Creek, was focused on the agricultural sector and the prosperity of regional South Australia.
He said last night's hung result felt like a big win.
"I think there is a large proportion of the community who would like to see some change," he said.
"I think it will probably be a pretty close end result.
"I think in eight weeks to make a seat a lot closer than what it had ever been before is a real achievement." Mr Pasin spent yesterday trying to win over undecided voters in the Barossa Valley area.
He said winning the seat would be a "long shot" but he hoped Barker would become marginal to make things "interesting".
BARKER PASIN (LIB) O'BRIEN (ALP) STACEY (NXT)IN DOUBT