Wynne, who had downplayed Liberal expectations ahead of the byelections, admitted her disappointment at the outcomes.

"This is a hard night," said Wynne. "We're not going to pretend that it's not a hard night for everyone who has worked so hard, not going to pretend that it is not a hard night in Niagara Falls."

A fired-up Hudak didn't admit any disappointment at seeing the NDP take Niagara Falls, and said the Conservatives captured the most votes of any party "by far" when ballots in both ridings were counted.

"This evening's results prove that the people of this province want change," Hudak said in Thornhill. "They sent the McGuinty-Wynne Liberals a clear message (that) they want leadership that will take decisive action, implement a plan to balance the budget and create jobs."

Wynne downplayed Liberal chances ahead of the votes, calling byelections "unique creatures" that allow people to safely lodge a protest against the government knowing she'd still be premier Friday morning and leading a minority Liberal government.

Losing Niagara Falls to the NDP is a major disappointment for the Conservatives, but is unlikely to change Hudak's demands for a general election as soon as possible.

The big question is will the NDP win be enough to convince Horwath to stop propping up the minority Liberal government and trigger an election, or will she seek a third budget deal with Wynne.

The premier had said she doesn't plan to call a spring election, and had promised to stick to her plan to introduce a budget even if the Liberals had won both byelections.

Wynne campaigned hard ahead of Thursday's vote, including a four-day, 12-city tour with stops in both ridings, as well as announcing $100 million in spending in Niagara Falls and promising a new hospital in the region.

The Liberals were blamed for the closing of the Fort Erie Race Track after they cut slot machine revenues to horse racing, but last week it was announced there would be a 2014 race season at the track. Fort Erie is Tim Hudak's home town, and the track was one of the largest employers in the Niagara Falls riding.

The Ontario Federation of Labour said Hudak should be embarrassed by his party's loss in Niagara Falls, and realize that the Conservatives union-bashing tactics are not playing with voters.

"His anti-worker, anti-union message is clearly not resonating in his own back yard... and this has got to be a tremendously embarrassing situation for the leader of the Opposition," said OFL president Sid Ryan.

By Keith Leslie, The Canadian Press