The Sky Blues hit the front when Alex Brosque converted a 40th minute penalty but had that goal was cancelled out when Shannon Cole bundled in an own goal just before the hour-mark.
The match looked destined for a draw until Iain Ramsay broke the heart of his old club with an injury time winner to consign the reigning champs to the foot of the table.
First versus last in the A-League saw a very even first 20 minutes or so with few chances that gave neither goalkeeper a whole lot to do.
Just before the half-hour mark though, Sydney should have taken the lead when Alex Brosque worked his way into the area before squaring up for Bruno Cazarine but the Brazilian somehow managed to miss from point blank range with his sliding shot in what was a huge let off for the league leaders.
Adelaide lifted their workrate after that scare and looked much more dangerous but unfortunately their opponents received a penalty when Adam Hughes pulled the shirt of Stephan Keller in the area and Alex Brosque stepped up to the spot and netted coolly for the opening GOAL.
The question would now be asked if Sydney were able to hold onto their lead as they had been unable to do in previous matches and if their next few minutes were anything to go by, they were determined to put the game away as soon as possible although it didn’t happen before the half-time whistle.
Adelaide were cut down when star midfielder Marcos Flores went down with a hamstring injury eight minutes after the break but at least it gave Travis Dodd his first piece of action for the season following a groin problem.
GOAL Sydney had made a habit of conceding in the second half and it occurred yet again when Lucas Pantelis made a nice run before laying it off to Sergio van Dijk but Shannon Cole’s overzealous defending saw the ball trickle past Liam Reddy and into the back of the net for a poor own goal to make it 1-1 in the 57th minute.
Seven minutes later, Hiro Moriyasu was inches away from putting Sydney back in front but Eugene Galekovic made a customary top-shelf save and then captain Terry McFlynn’s shot from the deflection was well-blocked by the Reds defence.
Moments after that, Galekovic came up with another brilliant diving save from a close range Mark Bridge shot and it seemed as though the reigning champs were sick of their poor recent results as they looked in the mood to come away with their first win of the season.
But Adelaide were able to break the hearts of Sydney when Robert Cornthwaite got forward with a strong run before cutting it back to substitute Iain Ramsay who rammed it home from close range to keep his former club at the foot of the table and in deep trouble whilst his current club are flying high on top.
Liam Reddy (gk), Shannon Cole, Seb Ryall, Stephan Keller, Scott Jamieson, Stuart Musialik, Hiro Morisayu (Gan 72’), Terry McFlynn, Mark Bridge, Bruno Cazarine, Alex Brosque
Subs - Ivan Necevski (gk), Brendan Gan (72’), Matthew Jurman, Hayden Foxe
Eugene Galekovic (gk), Cameron Watson, Iain Fyfe, Robert Cornthwaite, Cassio, Adam Hughes, Paul Reid, Joe Keenan (Ramsay 46’), Marcos Flores (Dodd 54’), Lucas Pantelis, Sergio van Dijk (Mullen 62’)
Subs - Nick Munro (gk), Daniel Mullen (62’), Travis Dodd (54’), Iain Ramsay (46’)