The Swans stamped their credentials for back-to-back flags with a 20.11 (131) to 13.14 (92) victory after the Kangaroos had led by 14 points at halftime.
Ben McGlynn booted his three goals and co-captain Jarrad McVeigh his two in the premiers' third-quarter ambush, continuing North's winless streak against Sydney since 2007.
Demoralised North Melbourne, who let Geelong run them down from 41 behind last weekend, are 0-3, while the Swans are unbeaten after early-season wins over strugglers GWS and Gold Coast.
The Kangaroos were impressive early and led by four at the first break and 50-36 at halftime.
But they had no answers as the premiers hit the accelerator to go to the final break ahead 106-59.
North tried to salvage something and booted the first three goals of the last as the Swans' pressure eased off, but it was too little too late.
Jude Bolton finished with four for the Swans, his first three coming at crucial times in the first half to keep his side in it, while Daniel Hannebery kicked three and Adam Goodes and Luke Parker bagged doubles.
For the Kangaroos, Lindsay Thomas booted three and Lachlan Hansen, Robbie Tarrant and Ben Cunnington two each.
Bolton had two by quarter-time but the Kangaroos led 26-22 after booting four majors to three.
The Kangaroos looked in control as flowing movements resulted in the first two goals of the second term through Thomas and Tarrant.
But in a near carbon copy of the first quarter, the Swans hit back with consecutive majors from Bolton, who bent a snap superbly, and Parker before Tarrant's second made it 50-36.
NORTH MELBOURNE 4.2 7.8 8.11 13.14 (92)
SYDNEY SWANS 3.4 5.6 16.10 20.11 (131)
GOALS
North Melbourne: Thomas 3, Tarrant 2, Hansen 2, Cunnington 2, Wells, Goldstein, Wright, MacMillan
Sydney Swans: Bolton 4, McGlynn 3, Hannebery 3, McVeigh 2, Parker 2, Goodes 2, Kennedy, Everitt, Jetta, O’Keefe
BEST
North Melbourne: Swallow, Wells, Cunnington, Goldstein, Mullett
Sydney Swans: McVeigh, Kennedy, Hannebery, Bolton, Malceski
INJURIES
North Melbourne: Liam Anthony replaced in selected side by Kieran Harper
Sydney Swans: TBC
SUBSTITUTES
North Melbourne: Kieran Harper replaced Sam Wright during the third quarter
Sydney Swans: Andrejs Everitt replaced Craig Bird during the fourth quarter
Reports: Nil
Umpires: Brett Rosebury, Simon Meredith, Nick Foot
Official crowd: TBC
