But Canterbury seized the initiative back in the second spell, and new All Black, second-five Ryan Crotty, capitalised after No10 Tyler Bleyendaal had freed his arms off a scrum dart.
Canterbury just denied Tasman the ball, and the home side were not helped by the merry tune, against them, on referee Sheldon Eden-Whaitiri's whistle.
There was hope for Tasman when replacement halfback Kaide Whiting reached out to score but Adam Whitelock put the exclamation point, if not the bonus point, on the display when he bustled over thanks to another Bleyendaal break off a scrum.
Canterbury have little time to regroup, hosting Waikato on Thursday night, while Tasman travel to Pukekohe next Friday to face the Counties Manukau Steelers.
Canterbury 28 (A. Whitelock 2, R. Crotty tries; T. Bleyendaal 2 cons, 3 pens) Tasman 13 (J. Lowe, K. Whiting tries; A. Symons pen). Halftime: 8-8.