A disastrous afternoon at the MCG has left Melbourne's finals hopes hanging by a thread and luckless forward Jesse Hogan's year potentially over, the Magpies ending the season with surprising 16-point win.
A left hamstring injury is the latest setback for Hogan, who returned just last week from a broken collarbone following his mid-season battle with testicular cancer.
The 14.15 (99) to 12.11 (83) loss is an even bigger problem for the Demons, who must now rely on the results of Sunday's games to determine if they play in their first finals series since 2006.
They remain in the eight as of Saturday night; a game ahead of eighth-placed Essendon, which hosts Fremantle on Sunday.
If the Bombers win, and West Coast beats Adelaide by approximately four goals, their hopes of a top-eight finish will evaporate.
They only have themselves to blame, having started like they each had one foot on a plane bound for a sunny climate rather than a team desperate to break an 11-year finals hoodoo.
Clayton Oliver (30 disposals) and Jordan Lewis (27) were good and Jack Watts provided some highlights on recall from the VFL, but the drive of Taylor Adams and three goals from Jamie Elliott – as well as two from Will Hoskin-Elliott – helped the Pies home.
Playing for pride and perhaps to save coach Nathan Buckley's career with finals not on the agenda, the Magpies were as impressive as the Demons were bad, their six-goal-to-one first term setting up the win.
As they hit targets and took marks – seven inside 50s to none, plus another Jeremy Howe mark of the year contender on the wing – the Dees, who were missing only Jack Viney, butchered the ball before the first break.
There were some early signs of life, like when Watts was involved in setting up Christian Petracca for a fast-moving goal midway through the term, but their lack of pressure was damning.
By quarter-time, they'd laid eight tackles to 14, and twice the Pies had waltzed through a pack of players to goal virtually unopposed at close range.
Jeff Garlett gave Melbourne a spark in the second term with two goals and Lewis and Oliver got their hands on the ball, but still the pressure lacked.
Not much had changed score-wise by half-time with the Pies leading by 28, but the Demons had at least showed they knew how to stifle their opponents and force them wide.
The last four goals of the third went Melbourne's way, which made things interesting with the three-quarter time margin 18 points, and when Cam Pedersen followed up Jake Melksham's third 15 minutes in, they were within eight.
However, despite a comical 30 seconds where Tyson Goldsack fumbled the ball over the Pies' goal-line only for Tom McDonald to kick in straight to Mason Cox – who then missed from point-blank range – the Pies had done enough early on.
It was Hoskin-Elliott's second at the 21-minute mark that put the result beyond doubt, and granted the Demons – and their supporters – a nervous 24 hours.
West Coast and Essendon, it's over to you.
Tom Phillips celebrates with the Magpie Army. Image: AFL Photos.
Collingwood: Steele Sidebottom's day looked done in the second quarter when he hit the deck on the city-side wing clutching his right hamstring. But he surprised all when he lined up on the field for the start of the third quarter with the leg heavily strapped. He played out the game although he did come off in the dying minutes.
Melbourne: Jesse Hogan is the big one, having limped off in the second quarter. Mystery initially surrounded his complaint as he didn't seem to acutely injure himself and simply jogged off and into the rooms. He returned to the bench but couldn't break into more than a hobble when he tried to jog with his teammates to the rooms at half-time, with the club later confirming a left hamstring strain. Cam Pedersen came off second best in a collision with Tom Langdon in the third quarter, but recovered to finish the game.
COLLINGWOOD 6.5 9.6 12.10 14.15 (99)
MELBOURNE 1.3 4.8 9.10 12.11 (83)
Collingwood: Elliott 3, Phillips 2, Cox 2, Hoskin-Elliott 2, Daicos, Grundy, Sidebottom, Broomhead, Adams
Melbourne: Melksham 3, Garlett 2, Neal-Bullen 2, Petracca 2, Watts, Hannan, Pedersen
Collingwood: Elliott, Adams, Hoskin-Elliott, Sidebottom, Treloar, Dunn
Melbourne: Oliver, Petracca, Lewis, Melksham, Jones, Watts
Collingwood: Sidebottom (hamstring)
Melbourne: Hogan (hamstring)
Umpires: Rosebury, Deboy, Pannell
Official crowd: 51,223 at the MCG