The GIANTS came into Wednesday's contest at USC Stadium needing to win their remaining four games to have any chance of finishing in the top four.
The last-placed Magpies pushed the Sydneysiders all the way but with Caitlin Bassett coming off the interchange bench to shoot 19-of-20 in the second half, the GIANTS held their nerve in a tense final quarter to stay in the finals race.
The GIANTS now sit two wins behind fourth-placed West Coast Fever with their finals fate to be determined when they take on the Adelaide Thunderbirds on Sunday, followed by the Fever in Cairns.
"We had a lot of changes on the court tonight," captain Jo Harten said after the GIANTS held off a determined Magpies side in the closing minutes.
"I think some of our young ones stepped up and played really well and I thought (Bassett) just absolutely stormed on there and made such an impact which is really pleasing."
The GIANTS opted to rest defender Amy Parmenter, the 23-year-old having played all but 30 minutes in the previous 10 rounds, with April Brandley entering the starting seven and Kristiana Manu'a shifting to wing defence.
But it was the Magpies' defensive pairing of Geva Mentor and Jodi-Ann Ward who made a big impact in the first quarter, the GIANTS' shooters making just 9-of-16 attempts as the underdogs took a 13-9 lead.
Harten and Kiera Austin found their range in the second period as the GIANTS opened with seven of the first 10 goals, setting up a narrow 27-26 advantage at halftime.
The Magpies refused to go away in the third quarter, with strong aerial work in the goal circle from Shimona Nelson helping the Magpies regain the lead.
But the GIANTS settled once coach Julie Fitzgerald sent Bassett into the game, the Diamonds captain contributing seven goals while Harten broke free to add three Suncorp Super Shots during the rebel Power 5.
Ahead 46-42 heading into the fourth period, the GIANTS answered every challenge the Magpies threw at them to keep their season alive.
Despite another mammoth performance from Mentor and strong games from midcourters Kelly Altmann and Molly Jovic, the Magpies remain with just one win for the season and play the high-flying Melbourne Vixens on Saturday.
Score breakdown
Q1: GIANTS 9 v Magpies 13
Q2: GIANTS 18 v Magpies 13
Q3: GIANTS 19 v Magpies 16
Q4: GIANTS 16 v Magpies 16
Nissan Player of The Match – Jo Harten (GIANTS Netball)
GIANTS shooting statistics
Kiera Austin: Total points 16 - G1 14/20 (70%) G2 1/3 (33%)
Caitlin Bassett: Total points 19 - G1 19/20 (95%)
Jo Harten: Total points 27 - G1 19/21 (90%) G2 4/8 (50%)
Magpies shooting statistics
Nyah Allen: Total points 5 - G1 3/3 (100%) G2 1/2 (50%)
Shimona Nelson: Total points 29 - G1 29/35 (82%)
Gabby Sinclair: Total points 22 - G1 10/13 (77%) G2 6/10 (60%)
Emma Ryde: Total points 2 - G1 2/3 (67%)
GIANTS starting seven: GS – Jo Harten GA – Kiera Austin WA – Maddie Hay C – Jamie-Lee Price WD – Kristiana Manu’a GD – April Brandley GK – Sam Poolman
Magpies starting seven: GS – Shimona Nelson GA – Gabrielle Sinclair WA – Molly Jovic C – Kelly Altmann WD – Melissa Bragg GD – Jodi-Ann Ward GK – Geva Mentor
