Progressive Conservative candidate Raymond Cho has won the Scarborough-Rouge River provincial byelection, held to replace former Liberal MPP Bas Balkissoon.

With all 234 polls reporting, Cho won the seat by 2,429 votes.

Eleven candidates ran in the Toronto riding, which has been a Liberal stronghold since its creation in 1999. They included Piragal Thiru for the Liberal Party and Neethan Shan for the NDP.

Following the win, PC party senior advisor Babu Nagalingam joked, "We will now be called Scarborough-Blue River," pointing to the signature blue colour of the party.

"Tonight there is a blue wave that has crossed the Rouge River in Raymond Cho," PC leader Patrick Brown said. "Tonight we made history. Thanks to your hard work we won a riding that has been a Liberal-held riding since it was created 20 years ago."

"This is only the beginning," Cho said, jubilant over the win. "With tonight's victory, this first step, the great leader Patrick Brown will become premier of Ontario [in] 2018."

'Of course we're disappointed'

Liberal Party candidate Piragal Thiru, who came second with about 30 per cent of the vote, was met with cheers and applause by loyal supporters.

In a statement shortly after the outcome was announced, Premier Kathleen Wynne said, "The result in Scarborough-Rouge River is disappointing and gives me cause for reflection. The good people of that riding have elected Liberals for many years. I'll be talking with our Scarborough members in the coming days, as well as our outstanding candidate Pirigal Thiru."

"Are we disappointed tonight? Of course we're disappointed. But we're resilient," Scarborough-Centre MPP Brad Duguid said.

"Byelections are a time to listen. As a party I think we've been in power for so long because we've been listening," Duguid said.

​In March, Balkissoon resigned from the seat he held since 2005, with little explanation other than to tell the Scarborough Mirror in April that he wanted to spend more time with family. Neither Wynne nor the party have spoken about the reason for his departure.

Sex-ed curriculum about-face didn't hurt PCs

Ahead of the byelection, Brown acknowledged that his changing position on the Liberal government's sex-ed curriculum could cost the party the seat but it clearly didn't hurt the PCs Thursday night.

​In March, Balkissoon resigned from the seat he held since 2005, with little explanation other than to tell the Scarborough Mirror in April that he wanted to spend more time with family. (CBC)

After promising last week to get rid of controversial changes to the curriculum, which encompasses topics such as same-sex relationships, gender identity and masturbation, Brown did an about-face on the topic on Monday, calling it a "mistake" to pledge to scrap it.

Before Brown's reversal Cho maintained the issue was one that his riding was passionate about.

"When I look at my riding, the huge majority are Muslim, Catholic, Hindu, Chinese. All these parents are quite concerned about this issue," Cho said.