Former Eagle McKinley bagged six goals and Edwards four, while Petrie - whose 2010 was derailed by foot injuries - made it safely through the club's first competitive hit-out of the year.
North Melbourne coach Brad Scott forecast some tough decisions at the selection table as the Roos try to find their best forward combination.
"It was really encouraging for him (McKinley) and I thought our forward line moved quite well and we’re going to have some selection dilemmas there because Ben Warren and Aaron Edwards were terrific too," Scott told www.kangaroos.com.au.
"We’ve got Lindsay Thomas who is a really dangerous forward as well so we’ve certainly got some options now."
Vice-captain Petrie spent time in the ruck and the backline, as well as in attack, in a performance that pleased his coach.
"He didn’t want to come off at all and he looked really strong out there," Scott said.
"I wouldn’t have minded if he didn’t touch the ball at all, as long as he got through all four quarters fit and healthy.
"He got through the four quarters and played quite well too."
In other positive signs for the Roos, talented midfielders Jack Ziebell and Liam Anthony were impressive after suffering serious injuries last season, although there was a scare when Ziebell received a heavy hit late in the game and left the field.
But Scott dismissed concerns of any serious damage.
"He is fine. He just got a knee in the back which hurt him for a couple of seconds but he’ll be okay."
Recruits Cameron Richardson and Shaun Atley were also prominent, while Matthew Campbell, Leigh Adams and Cruize Garlett all put strong cases for spots in the Roos' midfield.
"We’re really trying to expand our options through [the midfield] and Jack Ziebell we know can play through the midfield but we need to find some other guys to get in there and support Andrew Swallow and Daniel Wells and Brent Harvey," Scott said.
"We think we’re starting to find those guys and develop them as well.
"Shaun Atley was also terrific for us in there as well so for someone who has never played a game of senior football at any level, I thought he acquitted himself really well.”
It wasn't all good news for the Roos though, with Brady Rawlings sitting out most of the match after suffering a hamstring spasm early.
But Scott said the decision to keep Rawlings from returning to the field was mostly precautionary.
"With his age and experience we just wouldn’t risk him," Scott explained.
"The guys are really confident that he’ll be right to play next week so we’ll manage those guys that are in that age bracket through the NAB Cup.
"We don’t expect Brady to play more than two or three NAB Cup games anyway. Whether he plays next week or not, I’m not sure."
Scott said the club's aim this season is to compete with the competition's best.
"We were encouraged and feel that there were good signs, but we're mindful that we've got a hell of a lot of work to do to get up to our goal this year, and that is to be competitive against the top four sides."
North won't have to wait long to pit themselves against those top sides - their first NAB Cup assignment is against Geelong and the Western Bulldogs at Skilled Stadium on Sunday 20 February.
