A rare interchange infringement by North Melbourne in the final minute has handed Sydney the opportunity to snatch victory in their round 10 clash.
North Melbourne led by three points as the time remaining ticked below a minute, when a stoppage was forced deep inside Sydney's attacking 50.
The umpire stopped play to receive communication through his earpiece, after which he awarded Sydney a free kick and 50 metre penalty to hand Hayden McLean a shot from the goalsquare.
McLean converted and the Swans saw out the three point win.
It turned out the free kick was awarded because North Melbourne had used their 76th interchange for the match — one more than the allotted 75.
North Melbourne fans vented their frustration at the final siren, some booing the match officials and throwing rubbish onto the playing field.
Players of both sides were confused as the match-defining decision was made.
"The umpires just kept hold of the ball. I was wondering what was going on, maybe a free kick downfield or something," McLean told ABC Sport.
"And then he just looked at me and said 'Interchange free kick and 50 metres, your kick'. So we'll take that.
"The [shots at goal] in front are always the most nerve-racking. But I was glad to kick it, and it was a good win in the end."
The incident ends a dramatic week for North Melbourne that also saw their coach Alastair Clarkson step away from the club for a period of indefinite leave.
Interim coach Brett Ratten said North would not spend too much time dwelling on the mistake.
"We'll have a look at it during the week, and work out how we can do some things better. But we're not going to worry about that, we had some chances," Ratten said.
"There is sometimes chat about when we're getting close with the rotations, but there's nothing from a senior coach's point of view that I'm looking at for interchanges.
"There's so much going on in the game, so we just leave that to the bench."
