JUST when you thought Melbourne's season was back on track, the Demons go and rip out the hearts of their supporters in 20 minutes.

Melbourne coughed up five unanswered goals to a rampant Sydney in Thursday night's second term in Cairns, a spell that could prove costly in the Dees’ bid for a finals return.

SWANS STUN WOBBLY DEES Full match coverage and stats

Any hope of a fightback in the final term was killed off when Ed Langdon and Max Gawn missed easy shots inside 15m, allowing the Swans to waltz home 10.7 (67) to 6.10 (46).

It was yet another scalp for John Longmire's young outfit, led by experienced heads Josh Kennedy and Luke Parker who upstaged their more highly fancied opponents.

Melbourne remains clinging to eighth place before its finals rivals play in round 15, but lost more than three per cent from its record.

While it was the second term where the Swans did the damage, the Demons shot themselves in the foot in the opening stanza by failing to capitalise on the heavy wind at Cazalys Stadium.

Leading by three points at the first break, Melbourne then capitulated defensively in the second term as the young Sydney side’s run and carry put it to the sword.

The work of Nick Blakey and Jordan Dawson set-up easy entries for the Swans going forward with the breeze as Justin McInerney kicked the first two goals of his career in just five minutes.

The Demons were unable to make the most of the bulk of disposal in the third term and, despite chances in the final quarter, including throwing Steven May forward, blew their chances to mount pressure on the Swans.

In his second match back from a quad complaint, Demons veteran Nathan Jones had his thigh strapped in the third term and returned to the ground before sitting out much of the final quarter. The club later confirmed the former skipper had re-injured his quad.

Midfielder Angus Brayshaw spent a large portion of the third quarter off the ground with a foot injury that will need to be assessed, while Callum Sinclair suffered a knee injury in the dying stages that the Swans hope is only minor.

Have the Swans found a key back for the future?
Tom McCartin's move to defence was initiated at half-time last week and continued from the outset against the Demons. And like he did in the second half against Port Adelaide's Charlie Dixon, the 20-year-old looks well and truly at home in defence. With Callum Mills (calf) a late out, the Swans threw his replacement Hayden McLean forward and kept McCartin in defence. While he was been used as a defender earlier in his career, it's a move John Longmire can consider as permanent. 

Old stagers take it up to young bulls
Speaking pre-game, Swans forward Tom Papley identified the young Melbourne midfield as one of the best in the competition. With Christian Petracca in career-best form and supported by Jack Viney and Clayton Oliver it's easy to see why. But just a week after having the better of the Saints, the Demons midfield was shown up by Swans veterans Luke Parker and Josh Kennedy at the stoppages. Their bullocking presence allowed youngsters James Rowbottom, Justin McInerney and Nick Blakey to own the outside game.

Dees' fight for finals
After last week's win over St Kilda catapulted the Demons into eighth place, the loss to the Swans leaves their season delicately placed. Should they beat Fremantle off a four-day break on Monday night, Melbourne's season could well be decided in round 17 when they face fellow finals contenders Greater Western Sydney at the Gabba. Destiny is in their hands if they can go three-straight against Essendon to finish the year, provided they hold onto their percentage and the Western Bulldogs and Carlton don't come from the clouds.

SYDNEY                       2.0       7.2       7.4       10.7 (67)
MELBOURNE              2.3       2.4       3.7       6.10 (46)

GOALS
Sydney: McInerney 2, Parker 2, Rowbottom, Wicks, McLean, Hayward, Taylor, Clarke
Melbourne: Brayshaw, Spargo, Neal-Bullen, Harmes, May, Brown

BEST
Sydney: Parker, Kennedy, Lloyd, McInerney, Blakey, Taylor, Rowbottom
Melbourne: Langdon, Tomlinson, Gawn, Petracca, Brayshaw 

INJURIES
Sydney: Mills (calf) replaced in selected side by McLean
Melbourne: Jones (quad)