With their backs to the wall and widely dismissed as a premiership threat, GWS have stunned Collingwood to win through to their first AFL grand final after a four-point preliminary final thriller at the MCG.
The underdogs handled wet conditions to lead by a game-high 33 points early in Saturday's final term, but had to withstand a stirring late challenge from the Pies, who kicked the last four goals of the match only to fall agonisingly short - 8.8 (56) to 7.10 (52).
Leon Cameron's men set up a premiership decider against Richmond with the gutsy display in front of 77,828 fans, the vast majority of whom wore black and white and left the MCG broken-hearted at the pointy end of the season for the second year running.
It is the first time since 1980 that both the minor premiers and the second-placed team at the end of the regular season haven't made the grand final.
If the Magpies had managed to fall over the line, it would have been a controversial win after Josh Thomas was awarded a goal in the last quarter that appeared to be touched off the boot.
Thomas' next goal with seven minutes to go in the game sliced the margin to six points and set up a frantic finale with the ball camped in the Magpies' front half.
But Nathan Buckley's side couldn't find a way past the brave Giants, who hung on for the most famous win in the club's eight-season history.
"Did we anticipate being 33 points up with 20 minutes to go and then, all of a sudden, there's an avalanche from Collingwood? No," Cameron said.
"But it throws another set of circumstances at you and our boys are really proud. They wanted to find a way and they did.
"We've had our backs against the wall a little bit this year, but I said to our guys before they ran out: 'Enjoy the moment, play to the end and who knows what can happen?'
"We did play to the end and we're into a grand final."
Star players Toby Greene (suspension) and Lachie Whitfield (appendicitis) were ripped from Cameron's line-up in the lead-up to the clash, and co-captain Phil Davis (calf) was hobbled early.
Greene will certainly return and Cameron is confident Whitfield will too. However, Davis, who switched from defence to attack due to his limited running capacity, will need to undergo scans to determine the severity of the injury.
The Giants were simply tougher in the clinches, winning more than their share of ground balls and dominating the territory game in the first three quarters.
The Pies had been desperately disappointing for the most part, but somehow sprang to life after the last change.
They attacked in waves in a way that they hadn't managed for most of the match, Brodie Grundy leading he way with an incredible 73 hit-outs.
But this was a GWS story.
Nick Haynes was superb across half-back with 30 possessions and nine marks. Zac Williams gathered 25 touches with 10 clearances and a goal.
Josh Kelly (27 possessions) and Tim Tarranto (26) also made important contributions.
Master tagger Matt De Boer went to Scott Pendlebury and kept the Pies' skipper to 18 possessions.
"The overwhelming feeling for me is it's a waste, what a waste, unfortunately for the year," Buckley said.
"We've got to give credit to the opposition. They were harder for longer in the end.
"The scoreboard hurt us in the third quarter and we just weren't able to drag that back.
"So that's the game and, when you're speaking at the end of your season, it's a little bit difficult because you've still just lost a game of footy but you've also finished your season.
"So it's difficult to know exactly how to handle that at the time."