PORT Adelaide was unable to overcome an impressive North Melbourne outfit on Sunday afternoon, losing by 45 points at AAMI Stadium.

The Kangaroos trailed by eight points midway through the second quarter, but set up the win with a 20-minute period of dominance prior to half-time.

Inspired by in-form forward Drew Petrie (four goals) and skipper Brent Harvey (three goals) the visitors piled on five goals to Port Adelaide's one during the match-defining period to take a handy 18-point lead at the main change.

The Power were optimistic they had remedied their frustrating fadeouts after a competitive performance against West Coast last weekend, but slipped back into bad habits on Sunday and a more determined North Melbourne skipped away to an easy 21.10 (136) to 14.7 (91) win.

As has been the case too often this season, Port Adelaide was non-competitive for significant parts of the game.

The loss was the club's seventh 40-plus point defeat of 2011, prompting a visibly frustrated Matthew Primus to accuse his team of continually hoisting the "white flag".

"We just don't have the ability yet to remain consistently competitive," Primus said.

"That's been an issue for us for a few years now and it's still rearing its head. When the opposition come at us we fight back, but when they come at us again we just concede too much…that's the history that's been with us over the last couple of years.

"We need to keep getting better at it and our youth need to keep realising that when the momentum starts to shift we actually need to put our hand up instead of the white flag."

Petrie monstered Port Adelaide full-back Alipate Carlile, using his superior strength and judgement to keep his opponent away from the drop of the ball.

The rejuvenated goalkicker hauled in 11 marks, including nine contested, to fall just one contested mark short of the Champion Data record (10) set by former North Melbourne champion Wayne Carey in 2000, and one short of the Port Adelaide team's total (10) for the day.

Carlile's only reprieve came in the final quarter when he was forced from the ground with a hip complaint. Hamish Hartlett (shoulder) and defender Jasper Pittard (hamstring) were also injured in the loss, while Kangaroos utility Leigh Adams finished the game on the bench with an ankle complaint.

North Melbourne's dominance started in the centre square. Young Power ruckman Matthew Lobbe, who was a late replacement for Dean Brogan, started brightly but impressive Kangaroos big man Todd Goldstein got on top as the game wore on.

Goldstein amassed a career-best 54 hit-outs, including 14 hit-outs to advantage to give his midfielders first look at the stoppages.

The Power were forced to introduce substitute David Rodan, playing his first game back from a seven-week injury lay-off, into the game in the first term and appeared to struggle to run out the game, with underdone skipper Dom Cassisi and midfielder Matthew Broadbent both suffering from cramp in the last quarter.

Influential players
David Rodan enjoyed a successful comeback, amassing an equal-team high five clearances and chipping in with two goals. He'll be better for the match fitness.

What the coach said
Matthew Primus (Port Adelaide): "We just don't have the ability yet to remain consistently competitive. That's been an issue for us for a few years now and it's still rearing its head. When the opposition come at us we fight back, but when they come at us again we just concede too much and that's irrespective of whether we've got 10 first-gamers in or 10 200-gamers. That's the history that's been with us over the last couple of years. We need to keep getting better at it and our youth need to keep realising that when the momentum starts to shift we actually need to put our hand up instead of the white flag."

First quarter
Port's tackling pressure was ferocious early, with the Power registering 19 tackles in the opening quarter to North's nine. Danyle Pearce set the standard for his teammates, running down Ben Cunnington on the wing and laying four tackles for the term. Andrew Moore followed suit and reaped the rewards, booting the Power's first goal following some desperate forward pressure. Young Power prodigy Jasper Pittard was subbed out in the opening minutes with a cruel hamstring injury, while North's Leigh Adams was also in the wars after copping a knock to his right ankle. The Roos' tough nut returned to the field later in the term to boot an important goal and give North Melbourne the lead after a 50m penalty against Port's Matthew Broadbent. But a late goal to Power forward Jay Schulz, his second for the term, gave the Power a three-point advantage at the first change.

Second quarter
The second quarter was a tough arm wrestle, with both teams showing great willingness for the physical contest and trading goals at either end. But it was the Roos who assumed the ascendancy in the latter stages of the quarter, dominating the inside 50 count 20-11 for the term. Drew Petrie was creating some major headaches for Power defender Alipate Carlile, out-muscling him in the goalsquare and finding space on the lead. Quickfire goals to Petrie, Goldstein and Harvey saw North Melbourne build an 18-point lead before Daniel Stewart could stem the flow at the other end for Port with a steadying goal. Wells added another for North, but it was answered after the siren with a crucial goal to Jay Schulz to keep Port within three kicks.
 
Third quarter
It was all North Melbourne after half-time, as the Roos showed more desperation and hunger. With 33 more contested possessions than Port, the Roos smashed the Power into submission by booting six goals to Port's one. Cam Pedersen strolled in to goal unchecked just seconds out from three-quarter time to add more salt to Port's gaping wounds, extending the margin to 51 points by the final change.

Fourth quarter
With the result beyond doubt, the sting was completely drained from the game in the last term. Port Adelaide continued to move the ball laterally across the ground rather than attack through the corridor, frustrating the home crowd and the Power forwards alike. Goals to Hartlett, Thomas and Phillips made the scoreboard slightly more respectable, but the damage had been done. Boasting 13 separate goalkickers, North Melbourne eased to its fourth consecutive victory to continue its gradual resurgence up the AFL ladder with a commanding 45-point win.

The next four
Port Adelaide: Brisbane Lions (Gabba), St Kilda (AAMI Stadium), Melbourne (TIO Stadium), Bye


Port Adelaide             5.3   9.4     10.5    14.7    (91)
North Melbourne       5.0   12.4   18.8   21.10  (136)

GOALS
Port Adelaide: Schulz 3, Phillips 2, Rodan 2, M. Thomas 2, Moore, Gray, Westhoff, D. Stewart, Hartlett
North Melbourne: Petrie 4, Harvey 3, Edwards 2, Pedersen 2, Greenwood 2, Ziebell, Adams, L. Thomas, Goldstein, Wells, Swallow, Cunnington, Anthony

BEST
Port Adelaide: Cassisi, Pearce, Schulz, Phillips, Lobbe
North Melbourne:  Goldstein, Petrie, Ziebell, Wells, Adams, Pedersen, Greenwood

INJURIES
Port Adelaide: Dean Brogan (hamstring) replaced in selected side by Matthew Lobbe, Pittard (hamstring), Hartlett (shoulder), Carlile (groin)
North Melbourne: Sam Wright replaced in selected side by Kieran Harper, Adams (ankle)

SUBSTITUTES
Port Adelaide: Jasper Pittard (hamstring) replaced by David Rodan in the first quarter
North Melbourne: Shaun Atley replaced by Kieran Harper in the third quarter

Reports: Nil

Umpires: Nicholls, Schmitt, Hay

Official crowd: 17,275 at AAMI Stadium

The views in this article are those of the author and not necessarily those of the AFL or its clubs