Collingwood have confirmed their place in the AFL’s top four by crushing an injury-ravaged GWS Giants by 42 points at the MCG.

The Magpies kicked clear of GWS in the final term to run out 18.11 (119) to 11.11 (77) winners over a depleted Giants side.

A trio of serious-looking injuries to co-captain Phil Davis, Joel Patfull and Stephen Coniglio threatens the Giants’ promising season.

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Worst still, influential ruck Shane Mumford went down late with an ankle injury as the Giants limped to the line.

But for Collingwood, there are only positives as their fourth-straight win confirmed their credentials as top four contenders.

In midfield, Scott Pendlebury and Taylor Adams were damaging, Dane Swan was busy and Jack Crisp showed his talent.

Defenders Marley Williams and Tom Langdon were towers of strength in Nathan Buckley’s 50th win as Collingwood coach.

In his 100th match, Jesse White provided the spark for the Magpies after a scrappy start, kicking their first goal then turning provider for Travis Varcoe as Collingwood took a 13-point lead into the first change.

Dylan Shiel then produced an incredible burst to power GWS back into the contest.

The recently re-signed 22-year-old had 11 touches in 10 minutes, helping Cam McCarthy to kick the Giants into an 11-point lead.

Back came Collingwood with four straight goals to lead again at halftime.

The Giants’ injury woes began from the start of the third term, when Davis didn’t emerge from the rooms with a suspected broken leg.

Shortly after Matt Buntine collided brutally with teammate Patfull to further darken the day for GWS.

Goals to Jack Crisp, Travis Cloke and a fine running effort from Scott Pendlebury in the opening five minutes of the final term sent the Magpies home to a comfortable win.

McCarthy finished with four goals for GWS but Cloke outdid him with a goal after the siren to finish with a bag of five.

In Sunday’s other game, Leigh Montagna kicked a goal with 19 seconds left in the game to propel St Kilda to a stunning two-point win over Melbourne at Etihad Stadium.

Jeremy Howe put the Demons in front with just 41 seconds remaining with the first goal of a tense final term, but Montagna ran onto a loose ball in the goal square to hand the Saints a 12.13 (85) to 12.11 (83) win.

The result extends Melbourne’s losing streak against St Kilda to 11, with the loss their 21st in a row at the Docklands venue.

Montagna was outstanding with 28 possessions, with Nick Riewoldt important with four goals and 10 marks, although he copped knock to his knee late on.

Jesse Hogan enhanced his reputation as a superstar in the making with a career-best five goals for Melbourne, while Bernie Vince (38 possessions) and Nathan Jones (32) were influential.