Brodie Grundy has inspired Sydney to a sensational second-half fightback against his former side, edging 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.
The Swans had kicked just one goal in an unusually dour opening quarter, with the Magpies leading by 33 points at one stage before halftime.
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 put 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, with coach Dean Cox declaring: "I'm really excited about how mature this side can become."
"To turn into a team that if something's thrown, we can adapt and move and do it a different way.
"We're nowhere near the finished product, and we needed to work on multiple ways to try and gain ascendancy again."
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 fear the worst for youngster Oscar Steene.
Steene was in agony in the third quarter after his left knee buckled following a ruck contest with Grundy.
"It's not looking good, unfortunately," Magpies coach Craig McRae said.
"The early diagnosis is a full reconstruction, but we'll again have to get scans to confirm all that.
"He was really holding his own, and we had a lot of ascendancy from that.
"Not many teams can cope when their number one ruckman goes down like that against an opponent like Brodie."
Fan-favourite half-back Nick Blakey (one goal, 39 disposals) was also busy, 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.
Second-gamer Charlie West opened the scoring as Collingwood slammed through five straight majors for a 22-point lead at quarter-time.
Magpies midfielder Jack Crisp's desperate tackle on Swans star Chad Warner told the story of the visitors' control in a high-octane first quarter.
Warner - rarely matched in speed or flair by opponents - took a bounce as he broke away from the pack, only to be caught holding the ball by Crisp.
Unable to traverse the corridor freely, the Swans changed tack to the wings as heavy rain began to pour in the second quarter.
Collingwood adapted well, but defender Billy Frampton gave away a free kick - and a goal - for holding Charlie Curnow.
Jai Serong added another major for the Swans to keep them close, with the Magpies lamenting seven behinds alongside Ned Long's lone goal.
Grundy went up a gear as Sydney took control in the third quarter, but the Magpies refused to relent and set up a tense finish for the home side.
