An inspired display from an undersized Sydney defence has proved pivotal in their 26-point victory over a mis-firing Carlton to give the Swans' finals hopes a timely boost at the SCG.
Sydney entered the clash with an unheralded defence taking on the Blues' pair of Coleman medallists but made a statement in running away to a 11.11 (77) to 6.15 (51) triumph on Friday night.
Key defenders Robbie Fox, Aaron Francis and Lewis Melican - in his first match since the 2021 elimination final - were critical as they combined to restrict the much-lauded Charlie Curnow and Harry McKay to a single goal between them.
The Swans' (5-6) defence was also led by Jake Lloyd (35 disposals) and Nick Blakey (26) with swift ball movement that was too good for a Blues outfit that had trouble with their field kicking and when closer to goal.
"It was a team defence approach. Charlie took six contested marks but a few times 'Foxey' was probably giving away 15, 20 centimetres, so we wanted to make sure it was a team approach," Swans coach John Longmire said.
"We had the two McCartins (Tom and Paddy) and (Dane) Rampe out against a forward line like that, with some big boys in the front half that are as good at their craft as there is. It needed a system to get it done."
Young guns Chad Warner (29 disposals, two goals) and Errol Gulden (22, one) were superb for the Swans, while Luke Parker (21) was important in his 100th match as skipper.
Isaac Heeney spent more time in the midfield and often had a close eye on Carlton captain Patrick Cripps, as the Swans' 2022 All-Australian snapped out of a slump to gather 19 disposals and a season-high six clearances and 10 tackles.
Lance Franklin was goalless for the fourth time in six matches but Hayden McLean stood tall with four contested marks and two goals, while small forward Sam Wicks also slotted two goals in his first match of the season.
The Blues (4-1-6) have now lost four consecutive matches, and six of their past seven, as their hopes of a breakthrough finals campaign took another hit.
The Blues' key forwards could have had much more impact but for some wayward shooting. Curnow was the dominant forward on the field early but finished with 1.3 while McKay kicked 0.3 from limited opportunities.
Curnow had the better of the Swans defence in the air and hauled in six contested marks but was unable to make them pay on the scoreboard.
"It's pretty disappointing," Blues coach Michael Voss said.
"But we need to better at finishing. It has ultimately cost us the win. That leaves you pretty disappointed."
Emerging tall Tom De Koning helped stretch the Swans defence and impressed in his first match since round five with 13 disposals and a goal but was unable to influence the result.
Sam Walsh (31 disposals) and Adam Cerra (24) found plenty of the ball, while captain Patrick Cripps (19) battled hard despite some close attention from Heeney before limping from the field late in the game.
The Blues lost a key on-baller when former Swan George Hewett was knocked on the head by teammate Nic Newman's shoulder as the pair went to tackle Franklin early in the second term.
Newman was later sidelined with a hamstring injury while Ollie Hollands also sat out the final term with a shoulder issue.
Jesse Motlop was the Blues' leading goalscoring in a misfiring forward line with two goals but the visitors ultimately ran out of legs as much as chances.