Midfielder Luke Parker says his side's inability to stick to team structures during telling moments in games this season has proved way too costly, as the Sydney Swans were left to lament yet another narrow loss.

Leading by two points with less than a minute to play in a tense final quarter, Sydney lost control of the ball and then allowed the Western Bulldogs to find free men inside forward 50 for a final shot on goal.

Jason Johannisen took the kick; the defender going back calmly and slotting what proved to be the match-winning goal.

It was Sydney's third loss by less than two goals this season, and second which has come about by the last kick of the match including the after-the-siren defeat to Richmond in Round 8.

Parker, who was the Swans' best-on-ground on Saturday, said letting another win slip through the fingers was heartbreaking.

"We worked so hard to get ourselves back in the last quarter," he said.

"We know what to do in those last few minutes, it’s just frustrating that we haven’t been able to get our structures right in crucial times in a number of games this year and it’s cost us.

"(The Bulldogs) get there opportunity and they take that. We put ourselves in front but it was disappointing to finish like that."

Parker was influential in wrestling the momentum back from the Bulldogs who had booted six goals to two in the third quarter and established a 13-point lead at the final break.

The 2014 Bob Skilton Medallist finished with 34 disposals, five marks, 10 tackles and three goals, including a steadier late in the third term, while fellow midfielders Josh Kennedy (34, seven clearances) and Dan Hannebery (33, seven tackles) also lifted.

Lance Franklin kicked two of his five goals in the final term which got many of the 33,386 fans out of their seats at the SCG.

It was, however, the Bulldogs' pressure and intensity in the third quarter which was the difference.

"They got a bit of momentum, our pressure dropped off...and they smacked us around the contest," Parker added.

"It was good that we got ourselves back into the game, we had every opportunity to win that game, it just comes down to that last minute.

 "You can’t not do it for 95 per cent of the game and leave it up to the last five per cent."

Sydney face a six-day turn around before a Friday night encounter against Geelong at Skilled Stadium.