Having already lost to the Brisbane Lions, Carlton and Gold Coast, the Kangaroos couldn't afford another upset, and a superb third quarter ensured that wouldn't be the case at Canberra's StarTrack Oval.
The Roos kicked 8.2 to just one behind in the third quarter en route to a 19.12 (126) to 7.9 (51) victory that improves their record to 11-8 and solidifies their place in the top eight.
Drew Petrie enjoyed one of his best games of the year, finishing with 5.3 in front of 10,211 fans in Canberra, the Giants' second highest attendance at their second home.
Ben Cunnington, Ryan Bastinac and Leigh Adams all played a part in the victory, while Jack Ziebell showed some good signs as he strives to recapture his best form.
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For the Giants, Toby Greene had 35 touches in his 50th game – including 26 in the first half – and Heath Shaw, Devon Smith and Dylan Shiel had some good moments.
Jonathon Patton and Smith kicked two goals apiece for a GWS outfit that trailed by just four points at half-time before being blown out of the water.
"Overall we're happy," North coach Brad Scott said. "We adjusted to some things in-game that weren't going our way, which was pleasing.
"We've had some losses this year where we haven't been able to arrest the momentum, so that was good, but that (GWS) side is going to be a very difficult side to play from now on.
"I heard an analogy that they've been a baby that grew into a boy, that is now an adolescent and growing into an adult.
"They're very quickly looking like the talent they have on their list is going to come through."
GWS counterpart Leon Cameron looked visibly shaken after the match and was incredibly disappointed with the performance after half-time.
His side is beset by injuries, with Jeremy Cameron, Stephen Coniglio, Tim Mohr, Tom Scully and Lachie Whitfield among a host of Giants sidelined for the rest of the year.
But the Giants coach wasn't looking for excuses.
"Our boys are really flat," he said. "We know we've made some good progression and we understand there are a lot of injuries at our footy club at the moment.
"But it is what it is. That's footy and we have to be able to put up with that.
"Look at Hawthorn and how they cope with it.
"They're a hundred-year-old club, I understand that, but our young group has to learn staying in the game.
"If it's a good second quarter, you can't roll over in the third quarter. We've let the crowd down after half-time."
The Giants next face Melbourne at the MCG, while North will try to gather momentum ahead of the finals when it hosts the Western Bulldogs at Etihad Stadium.
Both teams had their chances in the early exchanges, but the Kangaroos showed greater poise in front of goal, kicking four goals to one for a 15-point lead at quarter-time.
Greene had 15 disposals in the first term alone in an eye-catching start to the match, while GWS tagger Tom Bugg held Brent Harvey to just four touches in the opening term.
North's lead reached 21 points in the second quarter as the expected script began to unfold, but the Giants then hit back hard, with Patton playing a starring role.
He kicked his first from a free kick against Michael Firrito in the goalsquare, before he showed his range by unloading a beauty from around 65 metres that landed on the goal line and bounced through.
That made it just a four-point game as North's stutters against lower-ranked sides reared their head once more.
But any thoughts of an upset were immediately extinguished by an outstanding third term.
Five goals straight within 14 minutes ended the contest, with Petrie kicking three for the quarter as the visitors marched to a 54-point lead heading into the last change.
From there it was all North Melbourne, holding the Giants to just 10 points after half-time.
GREATER WESTERN SYDNEY 1.4 6.5 6.6 7.9 (51)
NORTH MELBOURNE 4.1 7.3 15.6 19.12 (126)
GOALS
Greater Western Sydney: Smith 2, Patton 2, Kelly, Treloar, Hoskin-Elliott
North Melbourne: Petrie 5, Cunnington 3, Brown 2, Harvey 2, Ziebell 2, Turner, Adams, Firrito, Black, Bastinac
BEST
Greater Western Sydney: Greene, Shaw, Shiel, Treloar, Smith, Patton
North Melbourne: Cunnington, Petrie, Bastinac, Adams, Goldstein, Harvey
INJURIES
Greater Western Sydney: Lamb (ankle)
North Melbourne: Lachlan Hansen (hip) replaced in selected side by Aaron Mullett, Levi Greenwood (leg) replaced in selected side by Nathan Grima
SUBSTITUTES
Greater Western Sydney: Tim Golds replaced Jed Lamb in the third term
North Melbourne: Aaron Mullett replaced Aaron Black at three-quarter time
Official crowd: 10,211 at StarTrack Oval
