The Bombers were held scoreless in the fourth term after leading by 18 points at the last change, but narrowly survived 4.3 (27) to 3.6 (24) on Wednesday night.
A melee involving most players at three-quarter-time sparked by Essendon superstar Madison Prespakis's bump on Sofia Hurley with four seconds left in the quarter, seemed to jolt the Swans into action after the visitors could manage only one goal across the opening three stanzas.
After Sydney's Ella Heads converted a free kick for her maiden AFLW goal early in the fourth, Lucy McEvoy's slick spin and long-range snap inside the last four minutes cut the Bombers' buffer to less than a straight kick, before the full-time siren sounded with the ball entrenched inside the Swans' forward-50.
Onballers Brooke Walker and Stephanie Wales had 22 disposals apiece for Essendon, while Preskapis defied Tanya Kennedy's four-quarter tag to finish with 19 and have the Bombers within touching distance of the top eight.
Preskapis was the central figure in the scuffle, in which she was set upon by Alexia Hamilton and Kennedy, before others got involved.
"Really proud of the girls," Prespakis said.
"We fought really hard and Sydney came at us in the end.
"It (getting tagged) is really hard and does take a mental toll.
"Every single week I feel like I've got a thumb in my back everywhere I go.
"Woody (coach Natalie Woods) just says smile at them, take it as a compliment and do what you can."
Prolific Laura Gardiner (35 disposals), Hurley (27) and Kennedy (21) led the way for the Swans, who left their brave challenge too late.
Last week's goalkicking hero Daria Bannister scored a behind in the opening 30 seconds, matched at the other end later by Swans spearhead Bec Privitelli, the only two scores of a defence-orientated first quarter.
The Bombers finally started getting reward for their effort and cleaner ball movement, breaking the drought with two goals in 90 seconds - Paige Scott goaling following a brave mark in traffic, then setting up Ellyse Gamble.
Scott again set up Gamble, whose goalsquare pack mark and second six-pointer stretched Essendon's edge to 18 points at halftime.
Sydney started the third term by racking up seven of the first eight inside-50s.
The visitors finally notched their first goal through Privitelli and trimmed the deficit to 11 points.
Chloe Adams got one back for the Bombers and the margin was back out to three goals with a quarter to play, which proved just enough.
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