Sydney have pulled off a fourth-quarter fightback for the ages to defeat GWS by six points in a thrilling AFL qualifying final.

Trailing at every change, the minor premiers looked destined for defeat before Isaac Heeney launched from the centre box to make the scores level at 12.10 (82) at the SCG on Saturday.

Joel Amartey, quiet all game, kicked the match-winner with less than three minutes on the clock to claim a gritty 13.10 (88) to 12.10 (82) victory in front of 43,189 fans.

John Longmire’s men will host a preliminary final in a fortnight, while the Giants face a semi-final against the winner of the Brisbane and Carlton elimination final later on Saturday.

It is the first time the Swans have defeated their local rivals in September.

The ever-reliable Heeney was the hero for Sydney, kicking three goals, collecting 30 disposals and producing seven clearances. He also took an absolute screamer that could have been a contender for mark of the year, if it had not been in a final.

Defender Jake Lloyd (one goal, 32 touches), Chad Warner (27 disposals, seven clearances) and Errol Gulden (23, five) also came to life in the final term.

Tom Papley, playing his first match since sustaining a medial ankle ligament injury in round 19, booted three goals for the Swans.

Coleman Medal winner Jesse Hogan had the Giants on-song early with two goals, before a desperate James Rowbottom made it seven points the difference at the first change.

After a quiet build-up to the match, tensions finally boiled over in an all-in melee when Giants skipper Toby Greene was too slow to give the ball over to Papley for an after-the-siren free kick.

Papley then hit the scoreboard in the second term, but the Giants broke out to a 21-point lead after kicking three unanswered goals.

The popular Swans forward could come under fire after making contact with GWS head of football Jason McCartney at half-time.

Spurred on by a determined Heeney, Sydney began to regroup in the third term.

After claiming a spectacular mark on the back of Giants defender Jack Buckley, Heeney kicked his second of the match in a bid to lift his team.

But another Hogan goal kept the Swans at bay.

The home side’s woes continued when defender Tom McCartin dropped in on Lewis Melican as the latter attempted to mark the ball.

Aaron Cadman easily swept up the dropped Sherrin for his third goal as Sydney coach Longmire watched on in frustration.

The Swans opened the final term with three successive goals, before Heeney levelled the scores.

Hogan was sensational for the Giants, terrorising the Swans defenders all game to kick three goals and take eight marks.

Tom Green (32 disposals, 10 clearances) and Josh Kelly (27, six) did the heavy lifting through the middle for GWS, while young gun Cadman (three) was also electrifying up forward.