Outside backs Josh Buchan and Harrison Martin bagged three tries apiece in the one-sided romp.
The Magpies led 40-7 at halftime.
AU enjoyed their best patch during the opening quarter of the second half.
The Thode twins William and Oliver scored on either side of the break.
But the visitors faded badly.
Their fitness is lacking. They cannot seem to catch. They certainly cannot tackle and their offloads went to no-one or worse — the opposition. And they tend to go backwards when they have the ball.
The team has conceded more than 500 points in eight games.
The other three games were more evenly matched.
Dunedin held on to beat Taieri 38-35 at Peter Johnstone Park.
The win lifted them to the top of the standings and they collected the Speights Jug which is presented to the first round winner.
University kicked a late penalty to edge Harbour 48-46 in a thriller at the University Oval.
And Kaikorai recovered from a slowish start to beat Zingari-Richmond 43-22 at Montecillo Park.
