Toby Greene has reignited GWS's hunt for a maiden AFL premiership, booting five clutch goals to deliver his team a 12-point win over Richmond in a much closer match than last year's grand final.
GWS, desperate to make a statement after slipping to 13th on the ladder, were far from faultless but dug deep to prevail 9.8 (62) to 6.14 (50).
Greene, who returned from a sore shin, kicked a goal in every quarter to be best on ground in Friday night's arm-wrestle at Giants Stadium.
Last year's Norm Smith medallist Dustin Martin ignited a third-quarter comeback with two quick goals, while Shai Bolton threatened to snatch victory for the visitors in a frantic final quarter.
But it was Greene who fittingly delivered the sealer for GWS with a tick over five minutes remaining in the contest, crumbing what proved to be the only goal in the fourth term.
Lachie Whitfield, who was shifted off the wing and unleashed as a rebounding defender, and Josh Kelly were also dominant for the hosts.
Captain Stephen Coniglio, under pressure to lift given his club had dropped four of six games after the COVID-19 shutdown, was also heavily influential.
"It was backs against the walls sort of stuff," Greene told the Seven Network.
"Richmond are a bloody good side. They gave us a touch up last year. It was a good win ... hopefully we can build on it."
The triumph will not erase Greene's memories of the 89-point shellacking that the Tigers dished out in the biggest match of his career some 300 days ago, when the star forward was one of many Giants to have their colours lowered.
But Greene and his fellow forwards, who had few opportunities to bust the game open as their side's perennial struggles to get the ball past the 50m arc continued, showed why some pundits feel they can challenge for a flag in 2020.
"It's a great win but I didn't look at it that way, in terms of mental demons of last year's grand final," GWS coach Leon Cameron.
"They're a hard team to beat ... we've still got a bit of work to do."
Momentum shifted frequently and violently in this grand-final rematch, with the third quarter proving a perfect snapshot of the topsy-turvy tussle.
The Giants boasted a 27-point lead when Greene outbodied Dylan Grimes, marked a rainmaker and kicked the resultant goal - his fourth.
The Tigers responded with three goals in nine minutes, including a gift for Martin when Heath Shaw put the ball out on the full, to trim the hosts' buffer to eight points at three-quarter time.
Bolton, youngster Jake Aarts and key forward Tom Lynch then missed goals for Richmond before Greene stepped up.
"We had periods of complete dominance. We just failed to execute on the scoreboard ... we lacked a bit of polish," Tigers coach Damien Hardwick said.
Greene slotted his team's third goal in the 17th minute of the opening quarter - at which point GWS already had as many goals as they managed in the entire 2019 grand final.