NEWCOMER Rebekha Sharkie claimed the first scalp for a rising Nick Xenophon Team, easily winning over   Mayo voters "neglected" by Liberal Jamie Briggs.
Ms Sharkie said she was "shocked, elated and excited" to claim victory in the battleground seat stretching from the Adelaide Hills to the state's south. But she was clearly daunted by the prospect of being on the crossbench of a possible hung parliament, where she could be central to deciding which party would govern.
Mr Briggs, who had held the seat with a very comfortable 12.5 per cent margin after the 2013 election, conceded defeat early in the night after it became clear support for him had plummeted. 
With almost 60 per cent of votes counted, Ms Sharkie was ahead 56-44 per cent on a two party preferred basis.
"After a tough fight, tonight hasn't been our night. Thanks to those who supported me and my best to the new member, its (sic) a great electorate," Mr Briggs wrote on Twitter at 8.28pm.
Ms Sharkie put her win down to strong grassroots campaigning. "There was lots of door-knocking. I think today my car ticked over to 46,000km driven," she told the Sunday Mail last night. "I was talking to people rather than stuffing glossy brochures into their letterboxes.
"Over and over people told me they couldn't get in to see the sitting member (Mr Briggs). I know he was a minister for some time but they felt neglected." Ms Sharkie said voters were concerned about job creation, particularly for young locals, which they felt Mr Briggs had not fought for - especially in light of a Holden closure and the issue of the submarines contract.
Liberal Senator Simon Birmingham paid tribute to Mr Briggs, a "long standing friend and valued colleague".
"Jamie has great capacity in term of his policy skills, his advocacy skills," Mr Birmingham said. "Jamie's loss is a real loss for the Liberal Party and we will feel that deeply." Former prime minister John Howard expressed his disappointment Mr Briggs, a former staffer, had lost. Earlier in the day, Mr Briggs was confronted at a polling booth and had his election flyers spat on as the swing against him turned nasty.
Adding insult to injury, former state Liberal leader turned SA Labor Cabinet member Martin Hamilton-Smith handed out how-to-vote cards for Ms Sharkie at the Stirling polling booth where Mr Briggs cast his vote yesterday. Ms Sharkie, a former staffer for Mr Briggs, also worked in Mr Hamilton-Smith's office when he was opposition leader in 2008-09.
Mr Briggs managed to avoid an awkward run-in with Mr Hamilton-Smith, receiving a mostly warm welcome at the St Catherine's School booth. But as he lined up to buy a sausage sandwich, the mood soured when voter Caroline Fines barged past the media pack to ask: "Do you regret sending that photo of that lady to everybody? Do you wish you didn't do it? So that's where women are rated in your stratosphere is it?" Mr Briggs chose to ignore the questions, which referred to a boozy Hong Kong incident involving a female public servant, over which he resigned as a minister. That now infamous night set off Mr Briggs' fall from grace.
He was considered a rising star after Mr Howard took a shine to the assertive young adviser who worked in his office, along with wife Estee, between 2004 and 2007.
After the retirement of former foreign minister Alexander Downer in 2008, Mr Briggs beat nine by-election candidates to claim the blue-ribbon seat. Since its inception in 1984, the federal seat has been safely held by the Liberals - first by Mr Downer and then Mr Briggs.
In 1998, Redgum singer John Schumann, took a tilt as a candidate for the Australian Democrats, securing 21.8 per cent of first-preference votes.
The Liberals had been confident their brand would overcome anti-Briggs sentiment. But Doug Craig, from Mt Torrens, said he voted for Ms Sharkie because he and "quite a few people up here don't feel like we are being adequately represented by Jamie Briggs".
MAYO BRIGGS (LIB) DALLIMORE (ALP) SHARKIE (NXT)NXT GAIN