North Melbourne was 1-4 coming into the game and had lost its previous matches to the last four AFL premiers.
But the Power had a record five consecutive wins to start its season.
Despite that, the Roos were resounding favourites with most pundits, and opened the game in dominant fashion with a 33-point lead at the first break.
But as it has done in the past month, the Power responded and got to within 10 points in the last minutes of the game.
Led by Jay Schulz with three goals, Port Adelaide's resolve under acting senior coach Alan Richardson was important in constantly pegging back the Kangaroos' lead throughout the match.
It's inability to hurt the Kangaroos on the scoreboard was significant though with a return of just 11 points from six scoring shots in the opening quarter.
Travis Boak was a standout player for Port Adelaide with 30 possessions, 5 tackles and 12 clearances and undoubtedly the club's best on ground in trying circumstances.
Kane Cornes continued his strong possession-winning start to the season with 29 touches at almost 80% efficiency, including a massive 7 tackles.
Robbie Gray moved well in just his second full game back for the Power - returning one goal only - but looking very dangerous in attack.
Port Adelaide's focus now turns to Richmond who it hosts at AAMI Stadium next Saturday at 1:15pm.
Final scores
NORTH MELBOURNE 7.2 9.4 12.7 14.9 (93) def
PORT ADELAIDE 1.5 6.7 7.9 12.11 (83)
Goals: Schulz 3, Wingard 2, Neade, Renouf, Broadbent, Lobbe, Wines, Gray, Monfries
Injuries: TBC
Port Adelaide: Brent Renouf replaced by Paul Stewart in the third quarter
Reports: Nil
Umpires: Stewart, Meredith, McInerney
