All Black Ryan Crotty appeared to have played without any issues, scoring two tries in the first half before being substituted at halftime.
It was Southland's 24th loss in a row and the biggest win in the competition since 2012, another Canterbury thrashing of Southland.
Earlier the Canterbury women thrashed Wellington 57-19 in their Farah Palmer Cup opener.
Canterbury 80 (Tom Christie, Mitchell Drummond 2, Luke Romano, Ryan Crotty 2, Fergus Burke, Josh McKay 2, Mitchell Dunshea, Dallas McLeod, Luke Whitelock tries; Burke 4 con, Brett Cameron 6 con)
Southland 0
HT: 33-0