Perth Glory paid a heavy price for Steve Pantelidis' second-half red card as Sydney FC came from behind to win 2-1 at ANZ Stadium.
Glory looked well set to stay joint top of the A-League at the break, leading 1-0 thanks to Travis Dodd's 18th-minute goal and keeping Sydney's star import Alessandro Del Piero relatively quiet in front of 22,128 fans.
But the whole match changed just before the hour when Glory defender Panetlidis was dismissed for pulling down Brett Emerton in the box. Del Piero scored from the penalty spot and suddenly Sydney were on top.
And on 70 minutes Glory again shot themselves in the foot when keeper Danny Vukovic rolled the ball out to Liam Miller. The Irish midfielder turned into trouble, lost possession, and Socceroo Emerton chipped the ball over the stranded Vukovic to turn the game on its head.
"It was a bad decision to give (Miller) the ball there when he was getting pressed, it was not a good decision by Danny," Glory coach Ian Ferguson told Fox Sports.
There was further controversy near the end when the visitors were denied a penalty despite a handball from Rhyan Grant - all of which added to Glory's sense of frustration.
"It hit his hand. It's a definite penalty," said Ferguson, who reacted with fury on the touchline after his side's appeals were turned away.
"It was a guaranteed penalty and we didn't get it. I'm gobsmacked.
"I would like to get it clarified, what is a penalty.
"Because I've seen it so many times where a player raises his hands and it hits his hands and sometimes it's given, sometimes it not.
"His (Grant's) hands leave his side. It's a penalty, he's stopped the cross, but the referee said it was accidental."
Sydney FC coach Ian Crook agreed Glory were hard done to. "It wasn't deliberate but if you handball it in the area it should be a penalty," Crook said.
Skipper Jacob Burns was also upset with the call but admitted his side had let themselves down.
"It was a handball but that's the way it's going for us," he said.
"We should have seen the game out.
"In the first half we definitely controlled the game. The sending-off unsettled us."
After losing their first two games, the Sky Blues have now climbed into the top six and sit alongside Perth on six points.
But Crook wasn't too impressed with his side's display.
"It was disappointing in a lot of areas but in the end I have to give the boys credit because they dug in," he said.
"Somebody said to me the sign of a good side is a side that can win when it's not at its best."
The Englishman also praised his two goalscorers.
"That's why people like (Del Piero) and Emmo have gone where they have in the game, because they have a desire and an ability to be able to dig deep when things are going well," Crook said.
"Today both of them turned up trumps when we needed them."