A snap at goal by 34-year-old veteran Adam Flannery bounced through to give the Magpies the lead at the 27-minute mark of the last quarter.

``We hadn't been in front for much of the afternoon but the players willed themselves across the line,'' Devonport coach Max Brown said.

``It was an important win for our club.

``We haven't been in a position to knock off a top three side in the past few years and today we were able to achieve it.''

The loss was North Launceston's third for the year but will have no effect on its ladder position with the team remaining in third place behind Clarence and the Western Storm.

North Launceston appeared to be cruising to victory when it went into the half-time break leading by 24 points in a low-scoring game, but then a couple of masterly moves by Brown made the difference to Devonport.

``We were outplayed in the second quarter and had to do something to change the momentum,'' he said.

Devonport had lost its acting captain, Klay Griffiths, just before the half-time break with a knee injury and Brown then plotted his moves with speedster Jordan Smith moving on to North's playmaker Taylor Whitford and the decision to move defender Cory Plumbridge into the forward line.

``Plumbridge was lively for us and kicked an important goal in the third term as we got back into the game,'' Brown said.

Devonport whittled away at the lead in the third quarter and went into the final break trailing by just a goal.

Hawthorn premiership player Brent Guerra, playing his last game of the year for Devonport, bobbed up for an important goal at the start of the final term and suddenly the young Magpies knew they were in with a sniff.

``They didn't let their emotions get carried away with them and we matched it with North for the quarter and had our noses in front at the right time,'' Brown said.

Brown praised his 18-year-old ruckman, Alex Lee, who had a good battle with Daniel Roozendaal.

``Roozendaal was dangerous when the ball was deep in the forward line but I thought Alex matched him very well around the ground,'' he said.

The effort of Braden Van Buuren on North's Mitch Van Den Berg also didn't go unnoticed by Brown.

Flannery and Andrew Cox-Goodyear (North Launceston) both had their numbers taken for an incident in the second quarter.