The Swans have strengthened their hold on a top-four finish after dispatching of a lacklustre St Kilda by 97 points at Etihad Stadium on Sunday afternoon.
The 20.15 (135) to 4.14 (38) win ensures the Swans will earn a valuable double chance if they can beat the lowly Gold Coast next weekend.
The return of Lance Franklin and Gary Rohan from injury has further improved their finals hopes, although a hamstring injury to Nick Smith and the surprise substituting of Franklin in the third term means question marks linger.
Franklin was subbed off despite not appearing to be injured; a move that looked to surprise and frustrate the star goalkicker.
Smith limped off shortly after and spent the rest of the game icing his right leg.
Franklin had seven disposals, took three marks and kicked one goal in a rusty contribution.
Rohan, who has played one game since round 14, came on to replace Franklin and had seven disposals, and applied an impressive smother in the third term that resulted in a goal to Harry Cunningham.
While 10 goals to three in the first half set up the Swans’ win, five goals to one in the third made it hard for even the competition's comeback kings to contemplate a late fightback.
A final term flurry of five unanswered majors made it the Saints' biggest loss of the season, after they added just two behinds to their three-quarter time score.
The Saints were flat and had few winners.
Jack Steven and David Armitage worked hard in the middle but were hurt by poor disposal, while Jason Holmes again showed promise in the ruck against Canadian Mike Pyke.
But it was the class of Josh Kennedy (33 disposals, nine clearances), the midfield contribution from Dan Hannebery (39 disposals after a slow start), and the Swans' multi-pronged attacking structure that set the teams apart.
They had 10 goalkickers, with Kurt Tippett making life tough for Hugh Goddard with 3.4 and seven marks, although the young defender fought hard, and Isaac Heeney bobbing up with four goals.
In comparison, the Saints' forwards were painfully quiet.
Nick Riewoldt spent time on the wing but didn't really make an impact, Josh Bruce touched the ball just six times and Tom Hickey twice.
Retiring veteran Adam Schneider ended as their highest goalkicker with two, in his 228th – and last – AFL game.
In short, it was a tale of two teams heading in different directions with one game left; the Saints to off-season holiday destinations after a brave performance last week against Geelong, and the Swans to a likely top-four finish.
ST KILDA 1.5 3.9 4.12 4.14 (38)
SYDNEY SWANS 4.3 10.6 15.10 20.15 (135)
GOALS
St Kilda: Schneider 2, Riewoldt, Murdoch
Sydney Swans: Heeney 4, Tippett 3, Goodes 3, Mitchell 2, Reid 2, Pyke 2, Jetta, McVeigh, Franklin, Cunningham
BEST
St Kilda: Steven, Armitage, Roberton, Fisher, Savage
Sydney Swans: Kennedy, Hannebery, Mitchell, Heeney, Jack, Tippett
INJURIES
St Kilda: Nil
Sydney Swans: Smith (hamstring)
SUBSTITUTES
St Kilda: Tom Hickey replaced by Luke Dunstan in the third quarter
Sydney Swans: Lance Franklin replaced by Gary Rohan in the third quarter
Reports: Nil
Umpires: Bannister, Stephens, Ryan
