Sydney have found a chink in Fremantle's armour after unleashing a chip-mark game plan in an upset 17-point AFL win at Optus Stadium.
The Dockers dominated the opening quarter of Saturday night's clash and led by as much as 23 points in the second term.
But Sydney coach John Longmire implemented a significant tactical switch after halftime to turn the game the Swans' way.
The plan consisted of Sydney using a series of short chips to break through Fremantle's press, with the Swans racking up a mind-boggling 49 uncontested marks in the third quarter alone, and 88 all up for the second half.
Fremantle struggled to adapt and the 46,596 fans made their displeasure clear about the chip-mark tactics, with Sydney eventually running out 11.16 (82) to 9.11 (65) winners.
Chad Warner starred for Sydney with 35 disposals, seven clearances and a goal, while Erron Gulden booted two important goals from 21 touches.
The result lifted Sydney (11-6) into sixth spot and within a win of fourth-placed Fremantle (12-5) as the race for top-four berths heats up.
"We were just slow to adjust," Fremantle coach Justin Longmuir said of Sydney's chip-mark style.
"I think we were in good positions to defend, we just weren't active enough, we weren't reading the kickers' eyes.
"We got them pinned to a side and we just assumed they were going to kick it long to a contest, which teams have been doing.
"There was a bit of that, just assuming they were going to kick it long, without defending and forcing them long. We'll tidy that up."
Sydney forward Lance Franklin finished the match with just one goal from seven disposals, with Griffin Logue winning the head-to-head battle.
Fremantle's Brownlow Medal fancy Andrew Brayshaw was restricted to just six first-half disposals before finishing with 20 possessions and one clearance, while skipper Nat Fyfe (15 disposals) was also below his best in his split role.
Longmire praised the way his players adapted in the second half, saying the kick-mark style wasn't a hard directive going into the match.
"(It) just took shape during the course of the game," Longmire said.
"You have to find different ways to play, but that is off the back of pressure and structure and effort.
"Our players adjusted well in the second half. Full credit to them."
Sydney sprayed 1.7 in the second term before Franklin kicked truly after the halftime siren.
Fremantle only had themselves to blame for gifting Franklin the late goal.
With nine seconds remaining in the quarter, Fremantle forward Lachie Schultz kicked a goal from the top of the goalsquare.
The goal stood, but Dockers defender Jordan Clark gifted Sydney a free kick for the next centre bounce for bumping over Ryan Clarke two seconds after Schultz's goal was kicked.
The Swans went quickly into attack where Franklin took a contested mark and kicked truly.
Although the Dockers still entered the main break with a 15-point lead, Clark's moment of ill-discipline gave the Swans some important momentum that they built on in the second half.
