This result also stopped an unusually bad run at Mt Smart Stadium (four consecutive losses) and was their first win in Auckland for three months.
It was earned up front, with the Warriors pack gradually getting on top of their opposites.
Bunty Afoa thrilled with his back fence charges, Adam Blair was brutally effective and Simon Mannering found plenty of space.
The big men were helped by the back three, who provided invaluable momentum, with captain Roger Tuivasa-Sheck again brilliant on his dancing feet.
The Warriors rode their luck at times and persisted with the tactic of short goal line dropouts, which paid dividends twice as they regained possession.
Ken Sio, who always seems to make an impact against the Auckland club, powered through four defenders to open the scoring in the 11th minute, as the Warriors players seemed to get in each other's way.
It was an untidy first half-hour for the hosts. Passes were spilt, players were caught offside and a couple of kicks bounced just too long over the deadball line. The Warriors, in front of an expectant crowd, couldn't get rolling, as the Knights successfully slowed the play the ball.
It's a pattern the Warriors will have to break in the coming weeks, as the intensity rises and standards lift.
As happened last week, the home side's spark was provided by Tuivasa-Sheck. The fullback mesmerised the defensive line with a sideways jinking run, creating space for sleight of hand from Shaun Johnson and Gerard Beale, which eventually saw Adam Blair dive over in the 28th minute. It was a move at high pace, the kind that delights the men with the clipboards.
If that was good, the second try was even better, as long balls from Blake Green and Johnson outflanked a swarming Newcastle defence to open the door for David Fusitu'a. The Tongan winger, known for his acrobatics, displayed brute force to barge past three defenders to score.
Their momentum continued in the second half, when Green scythed his way over from 20 metres. The five-eighth isn't known for his running game but his teammates enjoyed his deception, engulfing him after he scored.
The Knights were unfortunate not to score through Aidan Guerra — who fumbled as he was forcing a Mitchell Pearce grubber — but otherwise were effectively subdued in the second half.
Warriors 20 (A Blair, D Fusitu'a, B Green tries; S Johnson 4 goals)
Knights 4 (K Sio try)
Halftime: 12-4
