The Sky Blues blew a two-goal lead with Avondale fighting back with two second-half Liam Boland goals, sending the game to extra-time.

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Andrew Redmayne was to blame for the equaliser, partially clearing a cross and allowing Boland to swoop.

Milos Ninkovic and Adam le Fondre netted in the extra-time period to help the A-League club progress.

Earlier Trent Buhagiar had scored twice in the first half for Sydney.

Crosstown rivals Wanderers knocked out reigning champions Melbourne City at AAMI Park.

Western Sydney went ahead through Oriol Riera with Roly Bonevacia making it 2-0 after 41 minutes.

City replied from a Riley McGree's 53rd minute effort but couldn't send it to extra-time.