Brodie Grundy has inspired Sydney to a sensational second-half fightback against his former side, overrunning Collingwood in a six-point wet-weather win.

With the score level at 9.14 (68) deep in the fourth quarter, Grundy steadied the Swans to set up an 11.15 (81) to 10.15 (75) victory at the SCG in Friday’s Sir Doug Nicholls Round match.

Swans celebrate(Getty Images)

The Swans had kicked just one goal in an unusually dour opening quarter, with the Magpies leading by 33 points at one stage before half-time.

Sydney roared to life with six goals to two in the third quarter, before key forward Logan McDonald benefited from Grundy’s rucking craft to finally launch the Swans ahead with an overhead goal.

Former Magpies ruck Grundy (one goal, 34 disposals, 47 hit outs) won the Goodes-O’Loughlin Medal for his best-on-ground performance in Sydney’s annual Marn Grook fixture in front of 40,627 fans.

Sydney (9-1) have now won seven games in a row to lead the league ahead of second-place Fremantle’s clash with Essendon.

Meanwhile, Collingwood (4-1-5) blew an opportunity to edge closer to the top six.

Already without No.1 ruck Darcy Cameron (ankle), the Magpies suffered another hit when youngster Oscar Steene went down in the third quarter with a knee injury.

Steene — who has been a revelation in his debut season this year — was in agony after his left knee buckled following a ruck contest with Swans counterpart Grundy.

Fan-favourite half-back Nick Blakey (one goal, 39 disposals) was just as busy as Grundy, while Tom Papley matched Logan McDonald with two goals.

Collingwood superstar Nick Daicos kicked two goals in the first quarter, but couldn’t spark his side with 27 touches.

AAP