Just when Sydney's season looked to have been revived, Hawthorn came and conquered the SCG to the tune of six points, as captain Jarryd Roughead landed a late bomb to throw the 2017 Swans back onto life support.
Despite Lance Franklin's best efforts, Hawthorn might well have rescued their own season after prevailing in a see-sawing final quarter, on the night where Indigenous Australians were honoured at the SCG.
Roughead marked 50m out on a 45 degree angle with just two minutes left on the clock. He went back and produced a booming kick which proved the most important of the night.
Just moments earlier Callum Mills had the chance to break the deadlock but tamely pulled his kick from 45m out, with Blake Hardwick marking to save the day for the Hawks.
Franklin's five goals, including three in a third quarter where he moved to 10th on the all-time goal-kicking list, looked to have hauled the Swans to a stirring win over a determined Hawks outfit looking to bounce back from last weekend's disappointment against Collingwood.
But Franklin's Indigenous counterpart Shaun Burgoyne and veteran Luke Hodge had other ideas.
Franklin and Burgoyne both wore number 67 in reference to the referendum 50 years ago where Australians voted to recognise Aboriginal and Torres Strait Islanders as real people.
"It's Indigenous round, you've got Bud who's played particularly well for Sydney, [and] Shaun, they've just been great ambassadors for the game," Hawthorn coach Alistair Clarkson said.
"It was a pretty significant milestone for all Aboriginal people but particularly those two boys, they've been the pin-up boys and carrying the can for their people for a long long period of time."
Burgoyne slotted two brilliant goals on the night, one on the run from 40m out hard up against the boundary, and another late in the fourth quarter from outside 50m that moved his side to one point shy of the Swans. A rushed behind just moments later levelled the scores.
Hodge meanwhile was Napoleonic on half back, marshalling his troops throughout and helping to form what at times proved to be an impenetrable wall.
"It was satisfying because we had our backs to the wall when we were challenged and we stood up when it was really important to step up," Clarkson said.
"They had momentum at the back end of the third quarter and the first 10 minutes to 15 minutes of the last. It looked like at that point in the game that the dam wall had opened.
"The resilience of the group to find a way to find their way back into the contest...that was the most pleasing part of the victory. It gives us a bit of belief, we've played okay without being brilliant over the last month.
"It's tough to beat Sydney at this ground. Really pleased for our boys. Nail-biting wins interstate are just really important for the morale of your group."
For long periods it was Buddy or bust for the Swans as they heaved it forward. Kurt Tippett and Sam Reid were unable to present with any danger, the latter missing the entire second half after failing his own concussion test.
"They didn't play well," Swans coach John Longmire said of Tippett and Reid.
"I thought we probably didn't play the sort of footy we wanted to in the first half particularly when they had the ball.
"We lost two players obviously. Lloyd in the first minute of the game. I thought in the second half there were some pretty courageous efforts by a lot of players.
"To come back and fight the fight after not playing that well in the first half and then losing two and digging in like they did. There were a few huge efforts, unfortunately not enough to hang on."
Sydney was behind the eight-ball from the opening minute after Jake Lloyd was forced off with concussion. He was tackled by ex-Swan Tom Mitchell and collided painfully with Liam Shiels' knee which forced him groggily from the ground to which he never returned, after a failed concussion test.
His composure and ball-winning ability at half back was sorely missed.
This was a spiteful game befitting of the recent rivalry between these two clubs, with both teams looking to avoid a seventh and potentially season-ending loss.
It will also go down as one of Hawthorn's great wins. They led for the most part, but looked to have been overhauled in the fourth quarter after two Isaac Heeney goals appeared to have iced it for Sydney.
But now it's the Swans who head into next weekend's bye knowing any more slip ups this year will likely be fatal.
Despite coming into the game off three strong wins, the Swans began poorly against a determined Hawthorn side which started powerfully as they did in last week's loss to Collingwood.
Hawks midfielder Mitchell picked up from his 50-touch game last weekend and had 10 to quarter time against his former side, each one met with plenty of jeering from the Sydney faithful.
Luke Breust opened the scoring in his 150th game with a slick finish from a free kick, and had himself a second later in the quarter when he marked unopposed 40m out.
Brendan Whitecross, Paul Puopolo and Jack Gunston also hit the scoreboard, while Franklin's two superb goals meant the margin never stretched too far. One was from 50m out up against the boundary line, the other a left-foot snap from deep in the pocket.
But the Hawks were clearly best in the opening term, playing a clean possession game that the Swans were unable to match.
Such was Hawthorn's control of the quarter, midfielder Zak Jones didn't collect his first touch until there were barely three minutes left in the term. Veteran Burgoyne did a superb job locking Jones out of the game.
Sydney looked to have it back on their terms midway through the second quarter after Tom Papley finished truly and Josh Kennedy slotted a timely captain's goal, but the Hawks wrestled it back.
Breust grabbed his third, James Sicily slotted his first and then Burgoyne kicked the goal of the game after stalking all the way around the boundary line and finishing on the run from 40m.
The Hawthorn veterans were controlling proceedings as they have done so many times against the Swans in the past five years.
Franklin's third quarter almost changed the game before Isaac Heeney stepped up with two goals in the final term, but it wasn't quite enough.