A Vancouver Sun headline says such a "mano-a-mano battle" would be a "high stakes thriller." We presume the writer was employing heavy irony. A verbal clash between Messrs. Harper and Ignatieff would resemble the scene in the comic strip "Cul de Sac" when Petey and Andre try to decide who will kick the soccer ball.
The last one-on-one debate in a Canadian federal election campaign was between John Turner and Brian Mulroney, in which then Prime Minister Turner had the disadvantage of being a gentleman.
The best exchange currently on television is the one between twin babies, available on Youtube, when you google either "Twin babies in conversation" or "Babbling babies."
The 18-month-old debaters top any current speaker on the election circuit.