The Swans were given a scare early by a determined Suns outfit that led for much of the contest until the hosts surged late in the third term to set up their 18.6 (114) to 13.12 (90) win on Saturday.
Midfielder Chad Warner sparked the match-turning period with a long-range left foot snap from the boundary, while a red-hot Will Hayward soon stretched the margin with his fourth goal for the Swans.
Warner was immense throughout and gathered 28 disposals with 15 contested and seven clearances, as James Rowbottom and co-captain Luke Parker offered plenty of support for the Swans.
Hayward was the most damaging forward on the field, though the sharp-shooting Swans will also be buoyed by their spread of goalkickers and the growing threat of twin towers Logan McDonald (three goals) and Hayden McLean (two).
Isaac Heeney booted two majors and looked sharp in the first half as the Swans struggled to keep pace with the Suns, while Nick Blakey (24 disposals), Tom Papley (24) and Jake Lloyd (23) were important with their run and carry.
The latest victory in a five-match streak propels the Swans (11-9-1) into the top eight and last year's runners-up will now hope to finish the weekend in the finals places for the first time since round five.
The Suns (9-12) started brightly and looked set to push the in-form Swans all the way until their third term lapse, while they will rue missed opportunities early in the final term that only yielded five behinds.
The young onball brigade of Matt Rowell (25 disposals), Sam Flanders (23) and Noah Anderson (22) battled hard, as co-captain Touk Miller (22) firstly limited emerging Swans star Errol Gulden's influence then made his own impact at the stoppages.
Goalsneak Malcolm Rosas was lively and booted three goals for the Suns, while Jack Lukosius and Levi Casboult both added two.
The Suns have now lost nine of 11 matches on the road this season, only defeating Richmond and West Coast away from home, as their hopes of a first-ever finals berth again faded away.
Gold Coast will be back at home to host Carlton next Saturday, while Sydney will look to continue their late-season surge when they travel to face Adelaide that night.