The Giants looked set for a season-ending loss when they trailed the Magpies by six goals with seven minutes remaining at the Sydney Olympic Park Sports Centre.

However, the team that have battled without injured captain Kim Green since round five staged a courageous rally to score seven of the last 10 goals of the game.

The decisive moment came with 17 seconds remaining and the scores locked at 51-51, when veteran Susan Pettitt threw a long pass into the circle where goalshooter Kristina Brice gained the ball and held her nerve to sink the winner.

The Giants now take on the Melbourne Vixens at Hisense Arena next Saturday after the minor premiers were sunk 56-55 by Sunshine Coast Lightning in the major semi-final earlier on Saturday.

The winner of the preliminary final will play the Lightning in the grand final on June 17.

For the Magpies, an inconsistent season has come to a shattering end.

The Giants had the better of a tight first half, but were mown down in the second and appeared gone.

A one-goal edge at quarter time became a six-goal advantage in the second term before Collingwood wrenched back the momentum to leave the Giants protecting a lead of 26-24 at half-time.

The refocused Magpies continued that streak with the first four goals of the third quarter to grab the lead for the first time since the opening term and held it by two goals going into the decisive final period.

Brice was the difference in the final decisive moment of the game.

The young goal shooter's selection proving a masterstroke by coach Julie Fitzgerald, leaving wing attack Susan Pettitt and goal attack Jo Harten to patrol outside the circle.

AAP

This story first appeared on Brisbane Times.