A double for striker Remy Siemsen and a goal from Lisa De Vanna in a moment Western Sydney Wanderers' goalkeeper Jada Whyman would rather forget completed the 3-1 win for the Sky Blues, who never looked like stumbling in the derby.

The win kept Sydney's hopes of reaching the W-League finals firmly alive after moving back into the top four while the Wanderers' chances of playing knockout football lengthened significantly as they slumped to equal last.

From start to finish, the Sky Blues outplayed their local rivals, who provided little resistance to Sydney FC's dominance in possession. Lead by the metronome in the middle of the park, Teresa Polias, Sydney made light work of the Wanderers' back line and created enough chances to have inflicted a heavier defeat.

They began their onslaught early and should have opened the scoring in the first few minutes. A defence-splitting through ball put De Vanna through on goal and the opener appeared certain to score when she easily rounded Whyman. However, the Matildas captain couldn't apply the simplest of touches to give Sydney the lead after a sensational last-gasp intervention from Wanderers defender Ellie Brush.

The Sky Blues didn't have to wait long to carve open another chance on goal. With Teresa Polias operating as the central pivot, the nimble midfielder played De Vanna through on goal inside the box. The veteran striker unleashed a fierce, left-foot drive into the corner of the net but a superb diving save from Whyman denied De Vanna once more. From the follow-up, Siemsen calmly slotted the loose ball into an empty net to give Sydney the lead.

Two minutes later, Siemsen doubled her tally with a powerful shot to make it 2-0 in the 24th minute.

The Wanderers struggled to test Sydney FC's goalkeeper Aubrey Bledsoe but should have clawed themselves back into the contest when Erica Halloway appeared to have been fouled inside the box, only for their penalty claims to be waved away.

Western Sydney would eventually get their chance from the spot late in the first half when Lo'eau LaBonta's drive was handled inside the box en-route to goal. Captain Ellie Brush rattled the roof of the net with a calm, yet powerful shot down the middle to make it 2-1 before the break.

Despite cushioning the blow with that late penalty, the Wanderers never managed to threaten Sydney FC further after the restart. A cagey opening to the second half provided few chances until just after the hour mark where a calamitous error restored the visitors' comfortable lead.

Seemingly free from pressure, Wanderers goalkeeper Whyman was haphazard with the ball at her feet and after a lengthy delay in clearing, she was tackled in possession by De Vanna. The Matildas star made no mistake in rubbing salt into the wounds of the young shot stopper by calmly finishing to extend Sydney FC's lead to 3-1.

Whyman went some way to making amends for her early blunder immediately after, holding firm to save a two-on-one opportunity to keep the hosts' slim chance of a comeback alive.

However, that save made no difference to the result as the Wanderers slumped to their fourth loss of the season.