The Liberal/National alliance has been returned to power in a State election where voters turned their back on Labor, delivering a landslide conservative victory.
Needing four seats to win government when polls closed at 6pm, voters shunned Opposition Leader Mark McGowan and the ALP.
By 8.30pm, the projections were that the Liberal and National parties had won a combined 39 seats, Labor had won 18 and two seats were undecided.
In his victory speech, Premier Colin Barnett thanked "the people of WA for their support and and the reelection of Liberal-National Government for four more years."
Referring to all candidates from all parties and independents and campaign volunteers across the State, he said it was "a great exercise in democracy".
"I congratulate Mark McGowan on what was an energetic and competitive campaign."
"We will retain all our seats that we won at the last election. We have also won a further seven seats with a few still up for grabs."
Mr McGowan conceded publicly at Labor headquarters in Rockingham just before 9pm.
He told the crowd he had rung Premier Colin Barnett a few minutes before and conceded.
"The Premier was gracious and we had a nice little chat," Mr McGowan said.
He said they talked about the events of the past few weeks.
"It was a hard-fought campaign. The truth of the matter is it was gong to be hard to win and we did our best in the circumstances."
He said the best years were still ahead of WA.
"This is a State of opportunity where anything is possible if you put your mind to it."
"I think our values as a Labor Party are sound.
“I think we did a good job,” he said. “We went out there and we were bold in what we stood for.
“I know that we need to provide those basic core services, those basic facilities where people live in an expanding, growing state like Western Australia, and that was the vision we took to the election.
“That was what we wanted to make sure people understood that we stood for and that we strived to achieve in the course of this campaign.
“All of those ideas are ideas that we will pursue into the future.”
Opposition Leader Mark McGowan gives his concession speech. Picture: Lincoln Baker/The West Australian
Labor had been courageous in putting out its ideas, he said, adding he was proud of the Metronet plan.
WA Labor's election campaign revolved around the Metronet train project but it was seen as an ambitious proposal and competed with the Liberal party's more piecemeal transport plans.
ABC election analyst Antony Green called the result in favour of the incumbents about one hour after counting began.
Federal Labor Minister Stephen Smith said from the outset that it was going to be a tough night for Labor.
Mr Smith said Labor had potentially lost 10 to 12 seats.
Collie-Preston is one of the few seats looking good for Labor, held by the party's Mick Murray since 2001.
In Balcatta, held by retiring Labor MP John Kobelke, the swing is towards the Liberals.
Hannah Beazley, the daughter of former federal Labor leader Kim Beazley, looks highly unlikely to unseat sitting member for Riverton, Liberal member Mike Nahan.
The Swan Hills area, the focus of some of the key campaign issues including the Ellenbrook rail line and Perth-to-Darwin Highway, seems certain to remain firmly in the grip of Liberal Frank Alban. Mr Smith acknowledged it was very tough to defeat a first term government, and had only happened twice in Australia's history.
In Perth, Labor's John Hyde was in trouble in Perth against Liberal Eleni Evangel.
Labor deputy leader Roger Cook said it looked "as though it's going to be a pretty long night" for the party, conceding a damaged brand in the West and inferior resources would play a part.
"We know that it was always going to be a tough fight and certainly the way the federal Labor Government is travelling is part of that equation," he said.
"The advertising by the Liberals over the last couple of weeks has been huge and the way they have been able to get out into
people's letterboxes means they had much more resources to draw on."
He said he was proud that despite the funding shortfall, Labor had still "set the agenda of the campaign".
Former treasurer Christian Porter said: “I knew we would win a majority but what’s gone on tonight is nothing short of extraordinary.
“This is a ringing endorsement for the Premier and the 4½ years of good work the Government has done.”
Liberal powerbroker Peter Collier said: “You can usually get a feel for a swing but I never had a feel for a swing of this magnitude. I find it staggering, It is just extraordinary.”
He said it sent a message to Prime Minister Julia Gillard that every policy that had impacted on WA had been emphatically rejected. Mr Collier said it was a massive warning to the Federal Government.
Labor frontbencher and re-elected member for Warnbro Paul Papalia said the apparent result was "really tragic situation" for WA.
"What we are going to have is an even bigger pool of people who are incapable of performing at an appropriate level," he said.
"It is not a good thing for Colin Barnett and the Liberal Party to have so much power and so little oversight because they control the Upper House already and what we've effectively seen haprpen is complete control of the Lower House.
"It's not quite a Queensland State of affairs but it's not that far removed."
A Newspoll published today pointed to a landslide win for the Liberal party.
Mr Barnett said earlier today the poll was encouraging, but he wasn't taking anything for granted.
“Those polls are across all electors and the Liberal party has done detailed polling in individual seats, and that shows a different story,” Mr Barnett said.
“There'll be a number of very close seats tonight.”
He maintained that at least a dozen seats hung in the balance, and that the Liberals would form another coalition with the Nationals even if the conservatives won the election outright.
Mr McGowan, who holds the seat of the working-class suburb of Rockingham, said he'd run the best campaign he could have.
“You can't get down, you can't get distracted - you have to focus on what matters to the people in the community and not be deterred by whatever comes along,” Mr McGowan said.
Both leaders spent the day visiting polling booths around the city in a bid to drum up last-minute support.
The WA Electoral Commission said voters surged to the polls early in the day, but a new computerised voter checking system at many centres kept waiting times to a minimum.
In the regions, WAEC staff in the Pilbara town of Karratha were stretched to their limit with the early turnout.
“We were hammered,” local returning officer Jill Johnson said.
“And in all my time working on elections I have never seen so many party officials and volunteers working so hard to canvass people's votes.”
On top of the strong morning turnout, there was a 30 per cent increase in early voting, with 140,000 votes ready for tallying as soon as booths closed.
There were some light moments, including a raft of fancy-dressed superhero and fantasy fans who attended the Oz Comic-Con convention casting their votes in the Perth city polling place.
And a complete bridal party arrived at the Riverton district's Shelley Primary School centre before kicking on for festivities.
Some Liberal MPs were confident of a swing that could deliver the Government as many as 30 of 59 seats in the Legislative Assembly.
While sources within the Liberals' campaign headquarters were quick to hose down those expectations, senior MPs were confident the party would hold Morley and win Albany, Forrestfield and Balcatta from Labor.
They were also optimistic the rural seat of Collie-Preston could be wrested from the grasp of veteran Labor incumbent Mick Murray.
At his last stop at Yokine Primary School, Mt Lawley Labor candidate and former health minister Bob Kucera said he was "quietly confident".
ALP candidate for Mount Lawley, Bob Kucera, talks to volunteer Amanda Rainey, left and senator Louise Pratt at the Yokine Primary School polling booth. Picture: Nic Ellis
"I think the response was much more positive than I expected it to be, particularly given the press and the polls over the last
couple of weeks," he said.
"I didn't get the agro that I was expecting and it's been positive and I'm quietly confident," he said.
Mr Kucera said the day felt similar to his narrow 2001 victory over Health Minister Kim Hames.
"We'll wait and see," he said. "It's going to be either a very tight contest or it'll be a bit of a bath the other way."
"They are a first-term Government and to take on a first-term Governent is always difficult. But we've had great policies and I think Mark and the team have run a magnificent campaign."
At Balcatta Senior High School Labor candidate Janet Pettigrew and Liberal candidate Chris Hatton have been doing some last-minute campaigning.
Ms Pettigrew said it had been a good day with lots of positive feedback.
She had been camped at the high school, the Balcatta electorate's busiest booth, for the day.
"I think it's going to be tight, certainly," she said.
"Generally speaking people have been very open and very friendly."
Asked what he gut feeling was about the result she said: it's too tight, too close to say."
"It's going to be very tight so we're keeping everything crossed at the moment."
She also felt the Statewide result would be tighter than polls would suggest.
Mr Hatton, whose teenage son Jamie was handing out campaign flyers, said it had been a "pretty positive day".
Mr Hatton said he had been to every polling booth in the electorate.
"Having run in 2008 the feeling is more positive this time," he said.
"It's actually a lot, lot better. Being local it's helped out a lot - people do know me well."
Although more than 1.41 million voters are enrolled this year, some 240,000 eligible people are not.
Electoral Commissioner Warwick Gately said getting ready for the big day had taken a huge effort, including preparing the largest count centre in WA history.
Premier Colin Barnett casts his vote at the Cottesloe Civic Centre. Picture: Michael Wilson/The West Australian
And it has gone out of its way to catch fly-in, fly-out workers and holiday makers, with polling booths at all of Perth’s six airport terminals, including charter services, staying open for 16 hours starting from 4am.
Labor leader Mark McGowan and wife Sarah arrive at the Rockingham High school to cast their vote. Picture: AAP
Mobile polling was offered in 83 remote sites around the vast State, including at indigenous communities, mine sites and stations, right up until 6pm (WST) on Friday.
Incumbent Labor member for Albany Peter Watson gets some encouragement from a constituent. Picture: Keir Tunbridge/The West Australian
Nationals party member Wendy Duncan had life size cut-outs at polling booths in Kalgoorlie. Picture: Mary Mills/The West Australian