Sydney coach John Longmire has lamented his side's slow start and a horror final term in the 50-point thumping from Melbourne.
After brushing aside Gold Coast and Hawthorn in the opening two rounds, the Swans failed to cope with a step up in intensity against genuine premiership contenders.
They conceded six of the first seven goals and though they got back within six points during the third quarter, fell away late in the game as the Demons clicked into party mode.
"We didn't jump out of the blocks like they did. They were clearly prepared for it in that first quarter," Longmire said.
"We were just a fraction off, which is all you have to be against good teams.
"They're a very mature, fierce, successful footy team and we've got to make sure we attack that head-on.
"We were just a bit off in that space and paid the price early."
Sydney gradually worked their way into the battle with improved pressure and contest work, and looked every chance to win when goals to the energetic Tom Papley and Errol Gulden dragged them within a kick.
But Melbourne booted four of the last five goals in the third quarter and slammed on seven to three in the final term.
Worryingly for Sydney, the Demons dominated contested possession (34-16) and the tackle count (14-5) in the decisive last quarter.
"We were minus 18 in the contest in the last quarter - that doesn't help - and their tackle pressure was pretty important," Longmire said.
"Sometimes you can look at different things but if you're not winning the ball and you're not tackling when they're winning it, it's not a good sign."
Sydney welcomed Lance Franklin back from a one-week suspension and while the spearhead kicked 2.2, he was kept relatively quiet by Steven May.
Fellow tall forwards Joel Amartey (0.3) and Logan McDonald (1.2) didn't have huge impacts.
"May's a star and he had four shots at goal, Bud, and I thought he competed pretty well to the end," Longmire said.
Sydney have a chance to get back on track when they host Port Adelaide at the SCG on Saturday night.