Analysts say Liberal leader Justin Trudeau, son of late Prime Minister Pierre Trudeau, needed to have a strong showing or risk falling further behind in the polls. A clearly prepared Trudeau aggressively attacked Harper and leftist New Democrat opposition leader Thomas Mulcair.
Harper spent most of the night under attack and acknowledged yesterday that Canada might be in recession. Harper blamed low oil prices for the slumping economy.
Analysts say Mulcair and the opposition New Democrats have a chance to gain power for the first time after the party won control of the legislature in Alberta, Canada's most conservative province, a few months ago.
Trudeau has trailed in third place in recent polls after Harper's Conservatives have run repeated attack ads saying the 43-year-old is not ready for the job.
The vote on the left may split between the New Democrats and Liberals. The first televised debate was seen as a key test for Trudeau, the son of the man whose legacy Harper is trying to erase.
Harper has managed to nudge a traditionally center-left country to the right since coming to power in 2006. He has gradually lowered sales and corporate taxes, avoided climate change legislation, supported the oil industry against the environmental lobby and increased military spending. He has also been a staunch supporter of Israel.
Nelson Wiseman, a University of Toronto political science professor, said Harper performed well in the debate despite repeated attacks and will hold onto his base support.
