Sydney turn it on in front of the SCG crowd to claim a big win in their push for top two over Collingwood.
Earlier, Richmond made light work of Hawthorn to seal their finals spot and Port Adelaide inflicted a dominant thrashing upon Essendon.
It was the Swans though who stole the show on Sunday, leaping into the top two with a commanding 27-point victory over the Magpies.
The Swans made a profound statement in the high-stakes match between two top-four contenders with an ominous four-quarter performance in the 11.11 (77) to 7.8 (50) triumph on Sunday.
With a top-two spot on the line this was arguably the most impressive of the Swans' six consecutive wins, which have come at an average margin of 40 points.
The Magpies' fairytale run in close contests rarely looked like adding another chapter with a 12th straight win as the Swans controlled the ball and territory early, then held the visitors at arms-length in the second half.
The Swans (15-6) could have settled the contest much sooner but for missing several simple shots that kept the Magpies dreaming of another improbable comeback in front of 44,659 fans — the second most ever at the SCG for a home and away match.
Isaac Heeney sparkled early in his 150th game, kicking 1.2 from eight disposals in the opening term, but it was the Swans' onballers who gradually out-muscled the Magpies while the McCartin brothers — Paddy and Tom — dominated the airways in defence.
Co-captains Callum Mills (29 touches, five clearances) and Luke Parker (25, eight) led the way in the midfield, with Chad Warner (25, five) and James Rowbottom (24, seven) also continuing their strong form.
The Swans had a spread of forward targets as Lance Franklin kicked three goals, while Tom Papley and Heeney finished with two apiece.
The Magpies lacked a similar goal threat, especially with Jordan De Goey a late withdrawal with a hip flexor issue and Jack Ginnivan subbed out at half-time after tweaking a hamstring.
Ginnivan had helped stop the Swans' momentum when they led by 21 points in the second term, the small forward converting from a controversial free kick for a high tackle, and his absence was noticeable after the main break.
Captain Scott Pendlebury (26 disposals) and Josh Daicos (25) battled hard but first-year gun Nick Daicos had his influence limited by the close-checking of Swans stopper Ryan Clarke, as the Magpies failed to match the measured ball movement of their opponents.
The loss leaves the Magpies (15-6) in fifth spot - outside the top four on percentage - and needing a win and other results to go their way in the last round to start the finals with a double chance.
Sydney will look to book a home qualifying final with a win over St Kilda on Sunday, while Collingwood need to bounce back against Carlton on the same day to secure a top four finish.
Power humiliate Bombers at Docklands
Zak Butters and Jeremy Finlayson have played starring roles to help Port Adelaide hand Essendon their heaviest defeat of the AFL season in an 84-point thrashing.
A run of nine consecutive Power goals from late in the first quarter to early in the third put the contest to bed before the visitors ran away with a dominant 23.8 (146) to 9.8 (62) win at Docklands stadium on Sunday.
It was the Bombers' biggest loss under Ben Rutten and the most points they have conceded in a match during his two years as coach.
Butters was everywhere as he kicked a career-best three goals from 25 disposals to go with six clearances and 10 score involvements.
Finlayson had a huge influence in a ruck-forward role despite losing the hit-outs to Sam Draper, finishing with two goals, 25 disposals, four clearances and 10 score involvements.
Mitch Georgiades responded to his week in the reserves with three goals alongside fellow tall Todd Marshall, who kicked two after a week out under health and safety protocols.
Sam Powell-Pepper slotted a game-high four goals.
Essendon midfielder Dylan Shiel (27 disposals, 12 clearances) won plenty of ball but the home side lacked players capable of taking control.
Mid-season recruit Massimo D'Ambrosio kicked the first two goals of his AFL career to keep the Bombers within eight points at quarter-time.
But seven unanswered goals to Port Adelaide in the second term blew the margin out to 51 points by the main break as Butters, Powell-Pepper and Connor Rozee ran riot.
The Power's 12.2 (74) was their highest first-half tally of the season.
The Bombers went 45 minutes without a goal until Archie Perkins ended the drought with a long-range set shot midway through the third term.
Further goals to Peter Wright and Nick Hind trimmed a touch of fat off the margin before three-quarter time, but the Power finished full of running and kicked nine last-quarter goals in the comprehensive win.
Port Adelaide will bring their season to a close with a Showdown against cross-town rivals Adelaide in round 23, while Essendon host finals-bound Richmond at the MCG.
Lynch kicks a bag as Tigers book finals spot
Richmond are finals bound after Tom Lynch's powerhouse eight-goal haul helped the Tigers to a 61-point thrashing of Hawthorn at the MCG.
The Tigers locked up their top-eight position with an ominous display on Sunday, racking up their third straight win as the rebuilding Hawks wilted.
Richmond had the game wrapped up at quarter-time after booting six goals to one, before storming to a confidence-boosting 20.8 (128) to 9.13 (67) victory in front of 59,338 fans.
Hawthorn trailed by 73 points at the final change, but they were able to keep the score respectable by winning the last quarter.
After missing finals last year for the first time since 2016, Richmond will be back in September as they look to recapture their premiership triumphs of 2017, 2019 and 2020.
They won't be in the top-four as they were during those flag years but with triple Norm Smith medallist Dustin Martin likely to return for the finals, rival teams will be worried about what the Tigers could do.
Lynch monstered the inexperienced and under-sized Hawthorn defence, going through three opponents before Hawks star James Sicily went to him during the third quarter.
The 29-year-old started in blistering fashion, slotting three goals in the first quarter as everything he did turned to gold in an equal career-best effort.
Lynch looked set to be the first player this season to bag a 10-goal haul after entering three-quarter-time with eight, but Sicily kept him goal-less in the last term.
Dion Prestia, Lynch's former Gold Coast teammate, was clearly the second best player on the ground as the Tigers midfielder with 29 touches and two goals.
The only sour note for Richmond was a foot injury to Jack Graham, with the premiership midfielder subbed out for Jason Castagna in the last term.
Richmond will finish off their regular season campaign with a Saturday night clash with Essendon, while the Hawks (8-13) will have a chance to ruin the desperate Western Bulldogs' slim finals hopes in Launceston.
