North Melbourne have all but secured September football with a 50-point win over a lukewarm Western Bulldogs side.

The Kangaroos’ 12th win of the season was built off two dominant spells in the first and third quarters, taking them to an impressive 17.9 (111) to 8.13 (61).

It wasn’t all roses for Brad Scott’s men, who lost Jack Ziebell with a knee complaint late and could have returning midfielder Daniel Wells on report.

Wells’ bump on Shaun Higgins collected the Bulldog’s jaw.

The Kangaroos impressed but were without a four-quarter effort, and saw forward Drew Petrie appear to dive for a crucial free-kick.

Two weeks after Petrie’s team-mate Lindsay Thomas was reprimanded by Scott for a swan dive, the Kangaroos could get an unwanted reputation with more efforts like this.

North Melbourne built their victory off a dominant first term.

Led by evergreen veteran Brent Harvey and clearance machine Andrew Swallow, the Kangaroos slammed on four unanswered goals in the opening 10 minutes.

The match resembled a training drill early on as Aaron Black’s two goals took North Melbourne to a 26-point quarter-time lead.

But either the sides swapped jumpers at the break, or the Bulldogs remembered their game-plan.

Harvey didn’t touch the ball in the second term as Brendan McCartney’s young side found their bark and recovered lost ground.

Marcus Bontempelli had 11 touches and kicked two goals in a powerhouse quarter, with 200-gamer Ryan Griffen and Koby Stevens also busy.

The Bulldogs reduced the deficit to 14 points at half-time, and could have been clear if not for wasteful kicking and Petrie’s questionable trip to the turf.

The ball was set to be bounced in the centre-square following Bontempelli’s major when Petrie went to ground in an innocuous contest with Jordan Roughead. The Bulldogs were punished with a free-kick going to the Shinboners’ skipper, who duly converted from 20 metres out, right in front.

A spell of four straight Kangaroos goals after the half-time break built a six-goal buffer.

Ben Brown proved a handful while Wells, in his first game since round five, showed glimpses of his elite skills.

Goals within a minute to Stewart Crameri and Luke Dahlhaus gave the Bulldogs a platform to enter the last quarter but a run to threaten the Kangaroos’ lead never came.

Instead Ben Cunnington kicked the last four goals of the game, including one after the siren, to close out a strong win.