Inexperienced North Melbourne youngster Robbie Tarrant capped an impressive showing up forward on Friday night with the winning goal in the AFL pre-season cup opener against Richmond at Etihad Stadium.

The Kangaroos came from nine points down with five minutes to play, with Drew Petrie and Tarrant kicking the last two goals to win 0.7.2 (44) to 0.6.5 (41).

But the first of three mini-matches, in a triple-header also involving Hawthorn, could come at a cost for both the Tigers and the Kangaroos.

North’s Leigh Adams had to be subbed off midway through the first of the two 20-minute halves, seemingly with concussion, after being knocked to the ground by Richmond’s Reece Conca.

The incident happened way off the ball, although replays were inconclusive as to exactly what Conca did.

More worrying for North, key defender Nathan Grima had to leave the ground close to halftime, after team-mate Jack Ziebell fell across his left knee, with the backman heading to the rooms soon after and not returning.

Those setbacks aside, there were some promising signs for both sides.

Tough Kangaroos midfielder Jack Ziebell impressed with his work in the packs and kicked a classy running goal to start the second half.

Tarrant, 22, who has played just nine AFL games in an injury-hampered first four seasons at the club, was prominent as a leading forward, while team-mate Aaron Edwards kicked three goals.

The Tigers would have been greatly heartened by the performance of ex-Adelaide ruckman Ivan Maric, who had the better of North pair Hamish McIntosh and Todd Goldstein in the hit-out count and did a few useful things around the ground.

Jake King had some good moments in a new midfield role, while young star Dustin Martin impressed with a game-high 11 touches and a goal.