The A-League premiers blew a two-goal half-time lead, with Liam Boland scoring a second-half brace to send the game to extra-time.

Goals from Milos Ninkovic and Adam le Fondre sealed Sydney's passage into the semis.

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“They were fantastic in the second half but first half was excellent from us," Corica said.

“Two-nil is a difficult one and we let them back in the game but we showed good character to come back and win.

“Good value and good fun (Avondale fans). That’s what the FFA Cup is all about.”

Ninkovic, who put Sydney 3-2 up, bemoaned his side's second half display.

“We knew it was going to be tough game but in first half we played fantastic, second half a little sloppy but we won the game," he said.

“We have three or four more weeks to get ready for the semi final and the league.

“We lost some good players but we signed some unbelievable players and they will bring something different to our team.”

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