Sydney coach John Longmire has slammed his side's "utterly unacceptable" performance that led to an overwhelming 112-point loss to Port Adelaide.
Looking to bounce back from four defeats in five matches, the Swans instead fell to their biggest loss since 1993 after being held scoreless for almost two quarters.
It is their fifth-worst loss in the club's VFL/AFL history and the biggest in Longmire's 13-year tenure as coach.
"It's completely and utterly unacceptable. It's not up to standard," Longmire said after their 22.16 (148) to 5.6 (36) loss.
"We've been in every game this year until last week, and we dropped away last week, and today didn't seem like it had a baseline to it.
"We just didn't come to compete and that's the very essence of the game.
"If you don't come to compete and fight, you get shown up no matter who you're playing."
The Swans were never in the contest, with Ken Hinkley's side slamming through seven goals to none in the opening quarter.
Port then surged to a 71-point lead before the Swans notched their first score, a rushed behind, midway through the second term.
Isaac Heeney broke through with their first major just before the main break but it did little to stir a lacklustre Swans unit.
Sydney were comprehensively beaten in all areas on the stats sheet, trailing 34 inside-50s to 69, 108 contested possessions to 135 and 295 disposals to 390.
"You can try and shift players around which we're trying to do but in the end, you have the very essence of trying to win the contest and put pressure on the opposition," Longmire said.
"If you do that, it leads to better skills and leads to better everything, but it's just we had nothing out there show.
"That was the disappointing aspect. There's got to be a fiercer pushback than that.
"It's pretty basic stuff."
Leading the league by four points, Sydney take on Collingwood, Essendon and Adelaide across the final three home-and-away rounds.
No VFL/AFL side have lost by more than 100 points and gone on to win a premiership, with Carlton losing by the exact margin to Essendon in 1945 before winning the flag.
Asked if he believes his side can rediscover their form before finals, Longmire said: "We need to. We absolutely need to.
"We're in a situation where we've got to. We've got to get to work. Where it sits at the moment is not good enough."