Skipper Roger Tuivasa-Sheck and his men have taken the club's best start to a campaign to 5-0, staying with St George Illawarra as the competition's only unbeaten teams.
Unfancied by many pundits at the beginning of 2018, the Warriors are firming as favourites to make their first finals appearance since 2011.
They again demonstrated their new-found defensive resilience against the Cowboys.
Last year's grand finalists have now lost four games in a row.
They also had plenty of hard-running from their outside backs, with Fusitu'a, Peta Hiku, Solomone Kata and Ken Maumalo all racking up more than 120 metres, with Maumalo leading the way with 159.
Halfback Shaun Johnson showed little effects of the groin injury, that sidelined him from last weekend's win over the Sydney Roosters, by landing all five shots at goal.
In front of a sold out Mount Smart Stadium the Warriors' win was set up by a fast start that shot them out to an 18-0 lead in the first half.
Maumalo finished off a Kata break with a leaping touchdown after just five minutes, before Fusitu'a followed up with a double on the other flank.
The first came from a superb Johnson pass, before some slick passing set up Fusitu'a's second of the night and his seventh of the season.
North Queensland finally scored close to halftime, with winger Kyle Feldt producing an acrobatic put-down.
The Cowboys continued to ask questions through the second half, and eventually found a way midway through the spell via fullback Ben Hampton.
Star half Johnathan Thurston, who had helped set up the try, landed his second sideline conversion to close the gap to eight.
However, Johnson had the final say, kicking a late penalty goal.