Defender Scott Thompson says North Melbourne's pressure was again on song in Friday's hard-fought victory.

In what was arguably the defender's best game of the year so far, Thompson credited the work of his teammates higher up the ground for making his job easier.

"I think our pressure the whole game was really good," Thompson said on Saturday.

"The forwards and the mids really applied that tackling pressure. (Andrew) Swallow and (Ben) Cunnington laying 14 tackles (each) is a super effort, even though we were out on our legs a little bit with the rotations, we still got the job done."

In front of almost 48,000 fans on the Friday night stage, the Roos continued their unbeaten start to the season.

"We've been getting scored against a little bit and we just showed this week we can do it the other way as well and restrict a team.

"The team defence was really good, keeping a team to under 50 (points) you're going to be happy with that. The pressure the midfielders and forwards put on really helped the backline achieve their goal."

Thompson spent much of the contest on Dogs' forward Jake Stringer, who wasn't able to boot a goal in the tight battle.

"He's a great player, but I have to say thanks to the midfielders and forwards for putting on that pressure.

"The ball entry wasn't very good to him on the day, so that helps me out and gives me a huge chance."

With six wins from the opening six rounds, confidence is certainly high at Arden St, but Thompson said the playing group knew there was plenty of work to do.

And while North's next three opponents, St Kilda, Essendon and Carlton, may not be in the top eight currently, there will be no easy games for North.

"Every game's tough and hard. Winning the first six games is a really good start to the season. You can't look too far ahead, everyone's been playing really well. If you're only five per cent off you can drop a match," Thompson said.

"We haven't lost a game yet so far, I think we've done enough to win all those games. We haven't played our best football but got over the line. We've definitely got things to improve on.

"We've got St Kilda in nine days time; it's Drewy's (Drew Petrie's) 300th, so we'll be wanting to get the win for him."

The number 16 also praised the efforts of fellow defender Sam Wright, who required treatment on an ankle injury in the first quarter.

"Sammy was obviously a bit sore but played out the game, it was a really tough effort by him to get back out on the ground. You never know with ankles, you could be right, you could not be. We'll just wait and see."

The deliberate out of bounds rule also raised some eyebrows during the Friday night blockbuster, with Thompson himself penalised for an attempted tap to teammate Nick Dal Santo that narrowly missed the mark.

"It gets frustrating, but it's tough for the umpires as well," he said.

"They (the umpires) have to get inside our heads and think what we're trying to do. I can see their point of view, they might think I'm tapping it out of bounds, but I think it's a good rule.

"Everyone knows you have to try and keep the ball in. Umpires will get better at it, players will get better at it too."