Collingwood have held off GWS in a one-point thriller to advance to the AFL Grand Final.
Jordan De Goey produced one of the best performances of his career as the Magpies posted an 8.10 (58) to 8.9 (57) victory in Friday night's preliminary final at the MCG.
Craig McRae's minor premiers were held goalless in the second quarter and trailed by as much as 17 points during the third.
But Collingwood, who will meet the Brisbane Lions or Carlton in the September 30 decider, stood up when the game was on the line despite losing Daniel McStay to a knee injury.
McStay kicked two goals before he was subbed out of the match at three-quarter time.
Mason Cox kicked Collingwood's only goal of the tense final quarter in front of 97,665 fans.
De Goey (34 disposals, 13 clearances) was superb and Nick Daicos (28, six) worked his way into his return match after seven weeks out with a knee injury.
Steele Sidebottom, Scott Pendlebury and Isaac Quaynor were also important for the winners.
Their combined displays overwhelmed GWS despite the best efforts of Tom Green (31 touches), Josh Kelly (33), Lachie Whitfield (26) and Toby Greene (two goals).
McStay and Jack Crisp gave the Magpies a perfect start with goals in the opening six minutes of the match before Daicos entered the fray to huge cheers from the black-and-white faithful.
The Giants couldn't muster a major until captain Greene broke the drought almost six minutes into the second term, taking a hand-off from Jesse Hogan to convert from 50 metres.
The crowd was left stunned as GWS booted four unanswered goals in the second term and held Collingwood to their lowest first-half score of the season.
The visitors led 4.4 to 2.6 at the main break.
Greene opened the second half with a brilliant snap and the Giants led by a game-high 17 points before former GWS forward Bobby Hill broke a Collingwood goal drought that had lasted more than an hour.
Finally the home fans found their voice again and the Pies piled on five majors to one in a 12-minute burst to hit the front before the final break.
The pressure was immense and even experienced field umpire Brett Rosebury wasn't immune.
He had to throw the ball up after incorrectly calling it out of bounds when it hand bounced on the boundary line and into Collingwood hands.
Cox and Hogan traded ice-cool set shots at opposite ends, with the latter cutting the Magpies' lead to one point as a tense final quarter ticked into time-on.
Despite De Goey being stuck on the bench in the final stages, Collingwood held on to seal their first Grand Final since the 2018 heartbreak against West Coast.