Mercurial Hawthorn star Brian Lake had one of the worst brain snaps of his AFL career as North Melbourne scored an impressive upset win.

Lake and his opponent Drew Petrie are certain to come under video scrutiny in the wake of North’s 16.12 (108) to 13.10 (88) victory on Friday night at Etihad Stadium.

The pair had an ugly-looking wrestle on the ground as the game erupted midway through the third quarter.

Lake’s horror night prompted a stinging assessment from former Hawks great Jason Dunstall during the match.

“It’s the worst game I have ever seen him play,” Dunstall said on Triple M.

Lake has been an outstanding recruit for Hawthorn and won the Norm Smith Medal as best afield in last year’s grand final win.

But Friday night’s game, and Lake’s third term in particular, brought back dark memories of Western Bulldogs coach Rodney Eade often blasting him for mistakes or brain snaps during matches.

Lake was not alone – several Hawks had off nights.

The Kangaroos were magnificent, bouncing back from last week’s shock loss to Brisbane with a fighting win.

Still, like Lake, North’s performance against Hawthorn again emphasises the vast gulf between their best and worst.

Petrie kicked five goals, while Lachie Hansen was outstanding in defence and Nick Dal Santo and Brent Harvey had plenty of the ball.

Jack Gunston stood out for the Hawks with six goals.

North led by six points at halftime and then went goal for goal with Hawthorn as the game went up a notch.

With the Hawks leading by four points, Lake gave away a stupid 50m penalty that gifted Petrie a goal.

Moments later, Lake and Petrie were wrestling on the ground as Ben Brown kicked another for the ‘Roos.

When Petrie kicked his third for the quarter, Lake was moved into attack and the Kangaroos led by 16 points.

Three more goals took North to a lead of 35 points at 23 minutes and the Hawks were in disarray.

The Hawks kicked the last two goals of the term and reduced the margin to 18 points in the last term, but North were never in serious trouble.

It was a testing night for Hawthorn coach Alastair Clarkson, who returned this week after recovering from a serious illness.

Bradley Hill pulled out moments before the opening bounce with a knee injury.

Then veteran midfielder Brad Sewell was subbed out during the first term with his second hamstring injury of the season.

It continues the defending premiers’ shocking run of injuries this year.

Adding to their problems, North started much better and led by 19 points late in the first quarter before two Hawthorn goals kept the game tight.