Canterbury actually looked a little tired in the first half, which was understandable given the short turnaround, and it allowed North Harbour to stay in the contest. The visitors still came under pressure, but their defence held well, and might have fancied their chances at halftime.
They chucked away, quite literally, a lot of that good work when Canterbury speedster Johnny McNicholl intercepted a Michael Hobbs pass early in the second spell and raced in under the posts.
At 17-3, Canterbury were never going to be overtaken and they extended their lead through tries to Nasi Manu, a second to McNicholl and Andy Ellis.
Harbour have shown glimpses of potential in their opening two games so far but they haven't been able to sustain it, although the Championship side were handed arguably the toughest draw of any ITM Cup side with their opening two matches against last year's Premiership finalists in Canterbury and Waikato.
Canterbury now enjoy a seven-day break before their next match against Wellington. Surely a rested side will mean an even more dangerous one.
Canterbury 36 (Johnny McNicholl 2, Robbie Fruean, Nasi Manu, Andy Ellis tries, Tom Taylor 4 cons, pen) North Harbour 3 (Bryn Hall pen). HT: 10-3.