I've noticed from my cursory knowledge of Australian politics that most Australian party leaders seem to fall in leadership challenges, whereas this virtually never happens in Canadian politics (the only case I can think of where this happened was when Stockwell Day defeated Preston Manning for the leadership of the CA).
PC 1983? Alliance 2002?
Ah yes I remember the Alliance in '02. But it's not really the same in 1983, as Clark himself called the election, rather being forced into one like say in Britain in 1990 with Thatcher.