NORTH Melbourne forward Aaron Black seemed just as happy with the four tackles he laid against St Kilda on Sunday evening as he did his first five-goal haul.

In his nine previous AFL games, Black's highest return had been three goals, but he had bettered that by quarter-time against the Saints, kicking 4.0 to spearhead North's match-winning 9.7 to 1.0 quarter.

The 22-year-old would finish the game with 5.3, 17 possessions and seven marks (two contested) to be one of North's best players.

In doing so, Black again showcased the cat-like agility, sure hands and reliable right boot that have given North's forward line another dimension since he was recalled in round five, against Hawthorn.

But it was North's defensive pressure against St Kilda that Black most wanted to take about when he spoke with AFL.com.au after the Roos' 68-point win.

"It was a make-or-break game for us and we worked a lot on our defensive pressure during the week," Black said.

"The Saints only got one goal in the first quarter and that was just terrific defence from the whole team, especially the backline.

"It was nice to kick four myself that quarter, but the main focus for us forwards was defensive pressure. I honestly got lucky that the ball got turned over and I happened to get on the end of it."

Black has kicked 15 goals in his six games this season to sit third on North's goalkicking table, behind Lindsay Thomas (33) and Drew Petrie (23).

In his first three games this year, Black had 14 tackles, but he had none against West Coast in round eight and just one against Adelaide the following round.

Black rediscovered his defensive mojo against the Saints, his four tackles second only to Thomas' six among North's forwards.

Sunday's game was the first in a year North has not played three talls on its forward line. With Majak Daw demoted to the VFL after a quiet fortnight, Black had only Petrie for aerial company against the Saints.

But the two combined well, with Petrie kicking his highest haul of the season, 4.4.

"I guess only having two tall guys down there we couldn't just bomb it in so much," Black said.

"We knew St Kilda would generate a spare (defender) down the line, so by chipping it around and using our foot skills and hitting up our smaller forwards at times, the forward line really worked well."

North coach Brad Scott agreed North's shorter forward line had functioned well against the Saints, but said the Roos had by no means abandoned a three-pronged tall attack.

"I think it's horses for courses in terms of the opposition you play and the conditions you play in," Scott said.

"It was really pleasing that we could change the structure up and it was still effective.

"But we're really keen to get Robbie Tarrant back and available… (and) Majak we know is just going to get better and better and better.

"We're pretty lucky … we've got a bit of a production line of key-position players."

Despite North's wealth of forward-line options, Black seems a good bet to cement a long-term spot in attack judging by Scott's comments.

"We've known Aaron Black's going to be a good player for a long time," Scott said.

"But we needed to get him physically conditioned and strong enough to withstand the rigours of AFL footy.

"But I think he's showing glimpses now of what he's capable of and the player he's going to be in the future."

After six consecutive senior games, Black said he was starting to feel more settled in North's forward line.

"Week by week you start to feel a little bit more confident," he said.

But in the next breath Black returned to his and North's theme of the evening – defence.

"I just thought tonight we really blocked well for each other and the forward line and the whole team in general just played a really good defensive game," he said.

Nick Bowen covers North Melbourne news for AFL.com.au. Follow him on Twitter: @AFL_Nick