Prab Gill's supporters erupted into dancing and cheering after a nail-biter in the Calgary-Greenway byelection last night, winning a crucial victory for the once mighty PC Party that might help fend off talk of a merger with the Wildrose.

"This is an exciting night for us. For me, for my family and for the PC party. This is huge," said Gill to loud cheers from supporters in a northeast Calgary banquet hall.

The real-estate appraiser beat the Wildrose's Devinder Toor, his closest rival, by a 335-vote margin. Toor conceded just before 10:30 p.m.

Follow along with live blog updates from the night

The race was an important one for the PC party. The seat was left vacant by MLA and former cabinet minister Manmeet Bhullar when he was killed on the QEII highway last year.

Bhullar was one of only 10 PCs who were left after Rachel Notley and the NDP won a majority in last May's election and ended more than four straight decades of Progressive Conservative governments.

"When we started this race a few weeks ago, I knew that we had enough to win this and carry on the work our dear friend Manmeet did," Gill told the gathered crowd.

Opinion polls and pundits had painted the race as a tight four-way contest among the PCs, Liberals, NDP and Wildrose candidates, but it came down to a fight between the two conservative parties as the night wore on.

The NDP candidate Roop Rai conceded after running third through most the night. In the end she came in behind Liberal candidate Khalil Karbani.

Wildrose candidate Devinder

Here is the look at the unofficial results from the top four candidates:

Prab Gill: 2,292

Devinder Toor: 1,957

Khalil Karbani: 1,870

​Roop Rai: 1,667

When asked earlier in the night what this meant for the future of unite-the-right initiatives in the province, interim PC leader Ric McIver said his party is the only one "looking after the money and looking after the people."

"I think we need to listen to the voters tonight and learn the lessons that they're trying to teach us all," he said.

Mount Royal University political scientist Duane Bratt said this is a huge blow to any merger talk.

"I think if the NDP had won it, that would have moved the two parties together. I think if Wildrose had won it you'd see more PC people leaving to the Wildrose," he said.

"But now I think you have two separate parties, one that's overtly conservative and one that's got a conservative wing and a progressive wing. And I think they're going to keep fighting it out."

Gill, speaking to his supporters, said many initially dismissed the PC party.

"When we started this byelection, people basically wrote us off. They said, 'A vote for PC is a waste of a vote.' We proved them wrong today, entirely."

He said friends would mock him when he said he was going to a PC meeting, asking if there still was a party.

"Guys, I hope you're listening tonight," he said. "And it's only going to get stronger."

Unofficial results from Elections Alberta pegged voter turnout at 29 per cent, down from 41 per cent in the 2015 provincial election.

Before the vote, the NDP had 54 of the 87 seats, the Wildrose party had 22 and the Tories had eight. The Liberals and the Alberta Party had one each.