Sydney FC coach Graham Arnold slammed referee Ben Williams after his side crashed out of the FFA Cup to Adelaide United on Tuesday.

A furious Graham Arnold has slammed World Cup referee Ben Williams after his Sydney FC side’s exit from the FFA Cup to Adelaide United on Tuesday night.

Two goals from Bruce Djite sealed a 3-1 win in extra time to book a semi-final spot after the Sky Blues had central defender Nikola Petkovic sent off for a high tackle on Fabio Ferreira three minutes from time.

Arnold labelled the decision an “embarrassment” to a TV camera from the sideline during the game after Williams decided to stop the fixture and only brandish the red card after an Adelaide attack had broken down.

“I feel for the fans and the viewers and most of all I feel sorry for the players,” Arnold said.

“I made my feelings known in the emotion of the game.

“It’s the first time I’ve seen a red card given after play on … they both get up and chased the ball.”

Adelaide coach Josep Gombau refused to comment on the performance of the officials but said Fabio had a “large contusion” on his inner thigh following the incident.

Arnold said the incident effectively determined the result of the match.

“I am proud of the effort … I wasn’t too happy with the first half but we dominated after … we would have won the game in 90 minutes with 11 men,” Arnold said.

Sydney will appeal to the FFA match review panel (MRP) over the red card with the Serbian stopper set to miss Friday’s A-League clash with Brisbane on Friday if the decision is upheld.

Arnold made seven changes from the side that beat Western Sydney Wanderers on Saturday including Sasa Ognenovski who was suspended just six hours before the game by the MRP after his swipe to the back of the head on Vitor Saba during that game.

The decision went unpunished at the time and Arnold hopes the club’s appeal will be heard and acted upon as swiftly as Ognenovski’s fate was decided.

“They got together quickly to suspend Sasa … we’ve got a game on Friday and you’d hope if they overturn it they’d do it quickly,” he said.

Gombau said he was pleased with his side’s performance but played down their positive start to the season which has seen them take four points from their first two A-League games and reach the last four stage of the FFA Cup.

“It’s early days. It’s not how you start it’s how you finish,” he said.