There were multiple injuries on both sides — including a provincial police officer who was kicked, punched and beaten with a stick. In an attempt to protect him, a police vehicle plowed through a projectile-tossing crowd.
With that, the epicentre of Quebec's stormy student protest movement shifted to Victoriaville, where the Liberals had moved their meeting.
It became instantly clear as the convention kicked off that the attempt to escape demonstrators by moving the event from Montreal would meet with limited success.
The standoff started with people tossing projectiles like smoke bombs, paint bombs and sticks in the direction of provincial riot police guarding the Victoriaville facility hosting the Liberal gathering.
When protesters pulled down a metal barrier outside the building, police pushed back. Using riot gear including stun grenades and chemical irritants, they shoved the crowd into surrounding streets.
By the time it was over there were numerous injuries — including one demonstrator reportedly shot in the face with a rubber bullet. None of the injuries was reported by police as life-threatening, although one protester suffered skull damage and four officers were hurt, two seriously.
Police also intercepted three buses on area highways and arrested a number of passengers. They would not confirm a number of arrests or disclose the charges laid, saying only that people were being released on a promise to appear in court.
Friday's demonstration transformed a community of 43,000 nestled between farmers' fields and the Trans-Canada Highway into an unlikely battleground, with protesters dancing to the music of a brass instrument while projectiles rained down from the sky.
It was a scene all too familiar to Montrealers. Downtown dwellers have become accustomed lately to human traffic jams and the sound of police helicopters buzzing overhead every night.
Protest groups responded to the Liberals' shift in venue by organizing rides in yellow school buses for the 170-kilometre journey to Victoriaville.
The disquietude forced a nearly one-hour delay in the convention, as some delegates complained of irritation from gases that had seeped into the building.
But when Premier Jean Charest finally took to the stage he was greeted with wild applause from his partisans. He defended his decision to hike tuition by more than 75 per cent and exhorted students to "end their boycott and get back to class."
The premier also cast his principal opponent as a popularity hound unwilling to make difficult decisions. He made sure to point out that PQ Leader Pauline Marois and her party have been wearing, on their lapels, the iconic red square that symbolizes the protest movement.
"Governing means making decisions that aren't easy, or popular.... We've chosen to defend the future of all Quebecers," Charest said.
"Pauline Marois made a choice to wear the red square." He concluded his speech with the words, "Leadership, leadership, leadership."
Meanwhile, only about one-third of the province's post-secondary students actually remain on a declared strike; the others have never joined the movement, or have gone back to class.
Polls suggest the weeks of unrest have not actually harmed the Charest government whose call for tuition increases appears, on the contrary, to have actually improved its public support.
Amid the clouds of smoke at Friday's standoff came a sliver of light. Student leaders were convened to Quebec City for emergency talks with the provincial government aimed at ending the three-month standoff.
With the semester at risk of being cancelled, the three main student groups and several union leaders were invited for talks with the government negotiator.
Authorities have avoided wiping out the semester so far, given the chain reaction of logistical challenges that would follow widespread cancellations.
After 12 weeks of walkouts, the student leaders and provincial government remain far apart and there has been little sign of a possible negotiated remedy. Expectations were being set low by participants as they entered the Quebec City meeting.
"We're coming here in good faith — we hope the same goes for the government of Quebec," one student leader, Leo Bureau-Blouin, said on his way into the meeting.
"Let's not get our hopes up, though: I don't think a 12-week crisis gets solved in a few hours."
The spokesman for the more radical group, the C.L.A.S.S.E., said he would take whatever formal offer was presented by the government negotiator and submit it to a vote from members.
The dim prospects for success were underscored by a message on the C.L.A.S.S.E.'s Twitter page. The group appeared to be planning for a protest at the Liberal party convention, rather than for a likely settlement.
"The pressure continues, the movement is close to victory," said the Twitter message from the C.L.A.S.S.E. "Let's disrupt the (Liberal convention) in Victoriaville!"
However, later in the evening, all the student leaders agreed to momentarily leave the negotiating table to address the television cameras. Each of them condemned the violence, urging protesters to remain peaceful and police to refrain from using excessive force.
-Written by Alexander Panetta in Montreal