North Melbourne is a different and more mature side in 2016 and its players won't sacrifice top spot on the ladder without a fight, according to coach Brad Scott.

The Kangaroos sit in top spot for the first time since 1998 and, in winning their opening four matches, have made their best start to a season since 2005.

In a match Scott conceded they would have lost in recent seasons, they fought off multiple challenges from Fremantle on Sunday to eventually prevail by 31 points at Etihad Stadium.

It was a performance that underlined a new maturity for the Kangaroos, who are also the highest scoring team this season after booting 20 goals for the second week running.

"We're a different side now … we're a side that is a lot more mature, and I don't think we give up games easily," Scott said.

"I think the guys have got a real attitude now that if you're going to beat us, you're going to have to play well because we're not going to hand you anything.

"Self-belief's a wonderful thing. There's no real supplement for self-belief … it's been building [for us] and it's fair to say it's as good as it's ever been."

North Melbourne was made to respond on Sunday evening after Fremantle clawed back an early deficit and hit the lead early in the third quarter.

The ability to stay calm and soak up Fremantle's momentum before returning fire was one of the most pleasing aspects of the win for Scott.

The coach was careful, however, not to overplay the significance of a 4-0 start and said the Roos were yet to play at their "optimum".

"It's a platform, but it's nothing more than that … it doesn't guarantee anything," he said.

"We know there are going to be significant challenges put before us for the rest of this year.

"What this season is throwing up is what a few of us have thought for a while and it is going to be really competitive.

"The AFL have got exactly what they hoped for, which is a fairly equalised competition where any team can take it up to any other team on any given Sunday."

Scott praised tall forward Jarrad Waite for another fine performance that netted four goals and has him placed equal second in the Coleman Medal race with 16 goals.

Waite was among the game's most influential players with 16 possessions and nine marks, also highlighting his defensive prowess with six tackles (he has laid 22 for the season, more than any other key forward).

"He's getting some reward offensively at the moment for all his hard work, but that's not what his game is built on – his game is built on defensive pressure," Scott said.

"You could make an argument that there aren't any better key forward pressure players than 'Waitey', and I wouldn't have thought that would be his legacy from early in his career.

"He's done a terrific job to make that the cornerstone of his game and he gets involved in the game offensively when he's doing that."