A furious Frank Farina blamed referee Kris Griffiths-Jones for costing Sydney FC a memorable derby win over Western Sydney Wanderers.
Alessandro Del Piero's first-half goal had the Sky Blues on course for a victory over their city rivals on Saturday, until Brett Emerton saw red for a lunging tackle on Shannon Cole 10 minutes after the break.
Griffiths-Jones had no hesitation in showing the stand-in Sydney skipper a straight red card, with Cole coming back to haunt his former club soon after with a superb equaliser, as the match finished 1-1.
Sydney did well to hold on for a point with just 10-men for the last quarter of the match, but the result means they must go to Brisbane Roar on Thursday and win to assure themselves of finals football.
Asked if Emerton's dismissal cost his side the win, a seething Farina said: "Yeah, I honestly think it did.
"We were 1-0 ahead I thought we were in control right up until the red card.
"We were looking comfortable and not really in any danger. That changed it for us.
"We've shown we finish games strongly, even with 10 men, and we had a great chance at the end, (Joel) Chianese's chance was a real good one."
Emerton's red card aside, Farina was critical of a number of Griffiths-Jones' decisions.
"Some of the yellow cards for both teams tonight were soft," the Sky Blues boss said.
"In a spectacle like this, in a big game like this, I thought it was an under-par performance (from the referee).
"People want to see an even contest. For 30 minutes at the end it wasn't an even contest, but at least we managed to get a draw, so I'm happy with that."
Sydney have now received six red cards in their last five away matches and Farina acknowledges it's an area of their game they must improve immediately if they are to have any success this season and beyond.
"Whether it's down to us and ill discipline or poor refereeing decisions, it's just not good enough," Farina said of the team's disciplinary record.
"We've got to improve that, particularly next season and for whatever remains of this for us.
"The last six or seven away games we've had six or seven red cards and you will struggle to win games if that's happening.
"And this was a game we had in our hands."
Defender Lucas Neill, who missed the last two games with a calf strain, was forced off at half-time with hamstring tightness.
Farina said the Socceroos skipper would be '50-50' to face the Roar in the do-or-die clash at Suncorp Stadium.