For the first time in this campaign, all Canada's main party leaders were on stage together in what is likely to have been the most watched TV debate in this federal election campaign.
So the stakes were high.
It was a crowded stage - the most leaders at one debate in Canadian political history: Liberal leader Justin Trudeau, Conservative leader Andrew Scheer, NDP leader Jagmeet Singh, Green Party leader Elizabeth May, and People's Party of Canada leader Maxime Bernier.
Did any of them standout from the crowd? Were there any performances sharp enough to finally shift opinion polls that have barely budged since the election was called mid-September? What topics sparked fireworks?
Here are some key takeaways.
Justin Trudeau v Andrew Scheer
The Conservatives and the Liberals have been locked in a dead heat for the entire campaign, so this was a chance to get some momentum before Canadians head to the polls on 21 October.
Both need to break that deadlock - and the two frontrunners frequently went head-to-head, occasionally talking over each other to the point of incoherence.
Andrew Scheer attacked Mr Trudeau straight out of the gate - slamming him as "a phony" and "a fraud" who doesn't deserve to be re-elected, and continued to go after him repeatedly on two issues that have been his Achilles heel with voters: the SNC-Lavalin affair and the blackface scandal.
With SNC-Lavalin, a federal ethics commissioner found the prime minister improperly tried to influence his former minister to prevent the construction company being prosecuted for corruption - a political crisis that saw Mr Trudeau slump in the polls earlier this year.
But the Liberal leader's electoral fortunes seem to have recovered despite old images of him in blackface surfacing in September.
And pivoting on Mr Trudeau's frequent attempts to link the federal Conservative leader with Ontario Premier Doug Ford, who has made unpopular budget cuts in the vote-rich province, Mr Scheer snapped: "You seem to be oddly obsessed with provincial politics".
Mr Trudeau proved willing to fight back and make his Conservative political rival his rhetorical punching bag, forcing him to defend his stance on social issues such as abortion rights.
Mr Scheer is "personally pro-life" but has repeatedly said that if elected, his party would not put forward or support legislation that would regulate abortion.
The Liberal leader also defended his record in government, including a strong economy, less poverty and low unemployment.