Sydney coach John Longmire was left looking for answers after seeing his side blown apart by St Kilda during the second quarter of Saturday's 28-point loss at Etihad Stadium.
Longmire described the two middle quarters as among his side's worst for the year as St Kilda scored 11 goals to four during this period.
Although the Swans led by nine points at the first change, they trailed by 21 at half-time, having conceded five goals to one, 17 inside-50s to a meagre three and 31 more possessions to their opponents.
Longmire went so far as to describe the two quarters as 'listless' and said the side desperately needs to find out why it failed to halt St Kilda's momentum.
"I didn't see that coming," Longmire said.
"What was the difference between the first quarter and the second term, that's what you try and put your finger on, (but) it's difficult to do immediately after the game.
"We were winning the ball and putting the score on the board and having shots in that first quarter and it was a complete turnaround at the start of that second quarter.
"And the disappointing thing is we didn't push back until the start of the last, it took that long before we got going again.
"Their pressure was outstanding for the whole game.
"The consistency of it didn't waver, whereas the consistency of our pressure really wavered.
"And that effects your cleanness at ground level, it effects your ball use it effects everything if you haven't got the consistency of hardness."
Sydney midfielder Kieren Jack felt when the Saints midfield, led by 250th game milestone man Lenny Hayes, got going it was almost impossible to stop.
"Second quarter we looked jittery," Jack said.
"We were fumbling the ball and it's not good enough from us.
"Their midfield certainly lifted. Hayes got going and we couldn't stop their momentum.
"It's something we've got to address this week.
"We had a good win against Melbourne but we can't go rest on our laurels."We've got to make sure when sides lift and lift the momentum we've got to be able to hold that and go again, tonight we couldn't do that."