But they overcame a shaky set piece - with a forward pack featuring four playing their first game for the province - courtesy of an impressive rearguard defence which bent but rarely broke.
"There was a bit of talk on Facebook and on the radio that they were bringing a few people down in buses," said Waikato flanker and try-scorer Rory Grice. "We knew they were coming down to take it off us, so we had to get up and smash them."
They certainly did on defensively in the first half, leaving Northland to head to the sheds with only three penalties to their name. Waikato were far more clinical when given a sniff and one of their first forays on attack ended with Grice the benefactor of extra numbers to the right.
It came against the run of play and, after Trent Renata converted, Northland were soon back on attack. Unsurprisingly, Rene Ranger was at the heart of much of Northland's positive play, with only a huge hit from opposite number Save Tokula preventing him from teeing up a reply.
"We knew he was going to be a threat because he always is," Grice said. "Especially on defence as well, he turns it over a lot. So we tried to keep him out of the game."
Ranger was involved again as Waikato scored their second. His poor clearing kick went straight to Grice and, after he began a counter-attack, Joe Webber darted down the right wing to cross untouched.
After an opening half of missed opportunities, Northland began the second spell determined to make amends. And it took only one minute for Sonatane Takulua to go under the posts, after Jake Paringatai came off the back of a scrum and put the halfback through a gaping hole.
The deficit was down to two and, after the sides traded penalties, both were guilty of blowing opportunities to apply real pressure as errors came to the fore. But Smith soon eased his side's nerves, burrowing over in the corner to clinch the game and put the
Shield on the line when Otago visits next week.
Waikato 31 (Grice, Webber, Smith tries; Renata 4 pens, 2 cons)
Northland 22 (Takulua try; Seymour 5 pens, con)
HT: 18-9