A Trent McKenzie long-bomb with the last kick of the game has gifted Port Adelaide a six-point win over reigning Premier North Adelaide in a SANFL trial game on Friday night.

The young Magpies showed remarkable fight to come back from five goals down in the second quarter and then again in the dying stages of the game to steal victory at the death.

Young forward Tobin Cox announced himself with four goals and Billy Frampton was a handful in the forward line with three as the Magpies proved too good at Alberton Oval.

The game started in blistering conditions with both sides being given additional rotations and drinks breaks mid quarter.

The Roosters squad of 31 gave them seven additional players to rotate off the interchange bench in the stifling conditions.

The site of the North Adelaide interchange bench swarming with 13 players was rather unusual.

It was a strong opening by the reigning premiers who had the first three goals of the match, despite having a player stretchered off with a leg injury inside the opening minute.

The visitors clearly weren’t hampered by the lengthy delay with Aidan Tropiano launching a long goal to kick-start the scoring just two minutes after the resumption.

The Magpies were made to wait until the 14th minute before Aidyn Johnson took a big pack mark in the goal square and converted the set shot to register their first goal.

He had his second just before quarter time after the players had broken for a drinks break and Jack Blair registered a fourth major for the Roosters.

An eleven point deficit at the first change soon became a 24-point margin as the Roosters piled on the pressure in the second term.

Former Power-listed forward Mitch Harvey was proving a handful for a slightly undersized Magpies defence with two second quarter goals, not that his size deterred Jack Strange – nearly half his size – who pulled off a remarkable spoil to prevent a third.

There were encouraging signs from the young Port side, including from the composed Joel Garner and Cam Hewett, Mitch Mead and Jake Patmore, who tried to create some run through the corridor.

Trent McKenzie involved himself, using his sublime left foot to switch play and drive the ball inside 50.

AFL rookie Tobin Cox proved he would be a handful for opposing defences in 2019 booting three consecutive goals to bring the margin back to just 12 points at the main break when it was 30 points in favour of the Roosters with eight minutes of the term to play.

Cox’s first was the highlight, a 30-metre set shot after taking a big mark over a couple of North opponents.

AFL draftee Boyd Woodcock booted his first goal against his former side early in the third quarter, one of three consecutive goals, including a fourth for Cox, which drew the Magpies level.

Goals to Kane Farrell and defender McKenzie, the latter a huge left footed bomb from outside 50 off one step, put the home side in front at the final change by eleven points.

But the Roosters refused to lie down. They booted four straight goals – the last to former Magpie Keanu Miller – to retake the lead.

The new rules regarding starting positions were having an impact and there was another swing to come when Woodcock kicked a second major and big Billy Frampton imposed himself in the forward line.

He booted consecutive goals to make it three for the night before Lachlan Smith put in a remarkable tackle to prevent North’s Strato Agorastos from notching an almost certain goal.

With scores tied and the darkness making it hard to see, even with the Alberton Oval lights blaring, it was left to McKenzie to have the final say - the siren blaring just seconds after he blasted home from long range to win the game.

The final quarter was the only term which didn’t feature a drinks break, with the quarter reduced from 25 minutes to 20.

It was a solid performance by Matthew Lokan’s Magpies given the range of new faces in his side and the fact that it was the first hit-out together for many of his players.

SCOREBOARD

PORT ADELAIDE               2.3         5.5         10.10    14.11    (95)

NORTH ADELAIDE           4.2         7.5         9.5         14.5      (89)

Goals

Cox 4, Frampton 3, Johnson, Woodcock, McKenzie 2, Farrell