Ontario's Liberals and Progressive Conservatives each held their own in two provincial byelections Thursday, but the Tories made history by electing the youngest ever member of the legislature.

Sam Oosterhoff, a 19-year-old Brock University student, took over 50 per cent of the vote in Niagara West-Glanbrook, a riding that had been held by former Progressive Conservative Leader Tim Hudak since 1995.

"Today we sent a very strong message to Premier (Kathleen) Wynne: people are fed up. People have had enough of soaring hydro rates. People have had enough of cuts to health care," Oosterhoff said to cheering supporters at his campaign celebration in Grimbsy.

Progressive Conservative Leader Patrick Brown said instead of campaigning on their record, the Liberals attacked Oosterhoff for his social conservative beliefs.

"The Liberals resorted to a smear campaign on Sam, but Sam focused on jobs. Sam focused on how we're going to get Ontario back on its feet," said Brown.

Brown had been accused of muzzling Oosterhoff after the home-schooled social conservative who lives with his parents won the party's nomination, in part by courting people opposed to the 2015 update to Ontario's sex-ed curriculum.

Brown himself had flip-flopped on the sex ed issue in a September byelection in Toronto's Scarborough-Rouge River riding, eventually saying he backs the curriculum changes. And he said Oosterhoff now supports the party's position.

But Oosterhoff repeatedly refused to say if he would try to repeal the sex-ed update if the Conservatives win the 2018 general election.

He described himself as "100 per cent pro life," but wouldn't say if he'd vote with the Conservatives to support a Liberal bill that would update the definition of families to recognize the rights of same-sex couples by using the word parent in place of father or mother.

Oosterhoff said his age was not an issue when he knocked on doors during the campaign, but he balked at questions about his home-schooling experience, and got defensive when pressed for details.

"You know what, the people who accepted my application and gave me big scholarships at Brock (University) seemed to like it okay," he said.

When asked how much he got in scholarships, the teen responded: "That's for me to know and you to find out."

Wynne had said earlier in the week that while she didn't want to specifically discuss Oosterhoff, it "disturbs" her that there are people in society who believe in "taking us back in time" by undermining work to ensure the rights of women and that kids have access to sex education.

In Ottawa-Vanier, Brown failed in his stated goal to embarrass Wynne in a riding the Liberals have held since 1971 by missing his target of coming within 10 percentage points of the Liberals.

Liberal Nathalie Des Rosiers -- former general counsel to the Canadian Civil Liberties Association, dean of civil law at the University of Ottawa and president of the Law Commission of Canada -- easily held the riding with about 50 per cent of the vote.

Andre Marin, the former provincial ombudsman, who ran for the Tories garnered about 30 per cent of the vote.

At Des Rosiers' victory party, Wynne said the new MPP will fight at the legislature for the values she has fought for her whole career, including a "fair and inclusive society."

When asked if she is worried Oosterhoff will work against those values, Wynne was coy.

"All I can do as a politician, as a human being, is to stand up for what I believe in and gather people around me who share the same values and we are working in our party for that inclusive society," she said.