1. Petrie and Lake clash
Halfway through the third quarter, Brian Lake and Drew Petrie were involved in a scuffle that is sure to attract the Match Review Panel's attention. Clearly on the back foot against his opponent, Lake was frustrated and pinned Petrie to the ground with a hand around his throat. As he fought to free himself, Petrie appeared to claw at Lake's face. The clash came as Petrie returned to form in stunning fashion in a season that has seen him struggle in front of goal. With 22.18 to his name ahead of Friday night's clash, he booted 5.1, getting free close to goal and making sure inaccuracy wasn't an issue. It was a night Lake would rather forget, but he might have time on the sidelines to ponder it.
2. Sewell's big challenge
Premiership midfielder Brad Sewell faces an uphill battle to cement his place in the Hawthorn midfield before September after another hamstring injury. The 30-year-old was struck down 15 minutes into Friday night's match, with another stint on the sidelines likely with just seven games to play before finals. Sewell didn't play until round 10 this year because of a hamstring injury, and he has now suffered three strains in two seasons. Injuries have been a constant challenge for the reigning premiers, with Bradley Hill withdrawn late on Friday night with knee soreness.
3. Roo redemption
It's become the story of their season – lose when they're expected to win and win when they're expected to lose. The Kangaroos have now beaten each of the top four teams – Hawthorn, Port Adelaide, the Sydney Swans and Fremantle – but they have let themselves down against battling teams like the Brisbane Lions. Does their record against the ladder leaders give them premiership credentials? Or does their tendency to trip up against the competition's battlers rule them out? They were the questions to emerge on Friday night. One thing we can say for certain is that Brad Scott's outfit is one of the most intriguing in the AFL.
4. Cracks as Clarko returns
The Hawks machine rolled on so smoothly in Alastair Clarkson's absence, but some serious cracks emerged in his first game back in the coach's box. On-field personnel played a role, but the first half stats told an interesting story. Two cornerstones of the Hawthorn game plan – kicking efficiency and uncontested marks – were missing in the first two quarters, with North Melbourne gaining an edge in both indicators. The difference in the two teams only grew in the third quarter, with North Melbourne starting to look like Hawthorn with its clean ball use and fanatical pressure. At the final siren, the difference in uncontested possessions was a massive 292-194.
5. Jacobs stakes claim
Out of favour at North Melbourne since crossing from Port Adelaide ahead of the 2013 season, Ben Jacobs might have found a way to earn a game on a consistent basis. His lockdown role on Isaac Smith was significant in the Roos' win, keeping the outside runner to just three possessions in the first half. Jacobs attacked the game like a player who knows his future in unclear, having failed to deliver since he was recruited by the Power with pick No.16 in the 2010 NAB AFL Draft. By full time he had kept Smith to 17 possessions and three inside 50s.
