The Magpies faced a 17-point deficit at the main break after struggling to match South's pressure around the contested ball.
But a third quarter surge saw the Magpies boot six unanswered goals to help the club into its first SANFL Grand Final appearance since 1999.
PORT ADELAIDE INTO SANFL GRAND FINAL
The victory did not come without a scare, as the Magpies were forced to lift its intensity another notch and hold onto the lead following a late Panthers surge in the fourth term, thanks to three goals to Brooksby, Cross and Eddy.
Port Adelaide was led valiantly by the skipper Steve Summerton, who managed to break away from his first half slump and lift his side to claim the win in a top shelf captain's performance.
Veterans Tom Logan, Paul Stewart and young gun Karl Amon also lifted and worked hard to win the contested ball and give the forwards plenty of supply.
This contrasted to the first half, where Port Adelaide lacked composure and crisp decision-making, with disposal efficiency at a low of 31 per cent.
The Magpies trailed in most of the key statistics throughout the day and could not capitalise on its chances up forward, despite leading the inside 50 count.
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In a low-scoring first half, it took until midway through the second term for the match to open up with South's run through the middle causing havoc for the Magpies' midfield to get the lead out to a game-high 17 points.
A late Summerton goal pulled the margin back to 11 points at the 23-minute mark and the Magpies looked to have regained its trademark run, but again the Panthers rallied and a second goal to Jake Veide pushed South Adelaide's lead back out to just under three goals at half time.
Similarly to their AFL brothers on Saturday night, the Magpies shot out of the blocks in the third term and began to produce classy and audacious runs through the centre of the ground to claw the deficit back.
Kane Mitchell and Aaron Young provided the speed and, combining with Darcy Byrne-Jones, Paul Stewart and Brendon Ah Chee the Magpies were able to snatch a 21-point lead at the final break.
In a knife-edge final term where the Panthers threatened to reel the margin back in again, Port resisted the momentum swing against them with a composed final 10 minutes to seal the result in true black-and-white fashion.
Port Adelaide will now face Norwood in the SANFL Grand Final at Adelaide Oval, on Sunday 21 September at 2.40pm.
SCOREBOARD
PORT ADELAIDE 1.3 4.5 10.10 13.12 (90)
SOUTH ADELAIDE 2.2 7.4 7.7 10.10 (70)
GOALS
Ah Chee, Shaw, Summerton, Stewart, Mitchell 2, Amon, Impey, A. Young
PORTADELAIDEFC.COM.AU'S BEST
Summerton, Young, Harvey, Mitchell, Ah Chee, Byrne-Jones
INJURIES
Bruggemann (shoulder)
EnergyAustralia Magpies Fans' MVP - Preliminary Final
