Melbourne Victory have posted their first-ever Westfield W-League victory over fierce rivals Sydney FC with a 2-1 triumph in a tense encounter at Leichhardt Oval.

Victory hit the front in the eighth minute via a brilliant Stephanie Catley free-kick but the Sky Blues got back on level terms after a classy Alanna Kennedy header just before half-time.

Both sides had their chances in a hard-fought second-half but an opportunistic goal from replacement striker Laura Spiranovic in the 81st minute proved the difference between the two sides.

Melbourne's second straight win lifts them within striking distance of the top four, while the Sky Blues remain in the top half of the table despite their first loss of the campaign.

The hosts suffered a blow before kick-off when dual international Ellyse Perry was ruled out with hamstring soreness.

Things got worse for the hosts in the when Catley found the target with a curling free kick to give the visitors the early advantage.

That sparked the Sky Blues into action, with Kennedy, Samantha Kerr and Simon all firing shots on goal in a dominant period for the hosts.

The dangerous Jess McDonald almost doubled Victory's lead against the run of play on the half-hour with a dangerous header that forced Sian McLaren to dive at full-stretch and pull off a classy save.

But Sydney quickly reasserted their dominance, peppering Victory's goal before Kennedy finally found the back of the net with a clinical header off a pin-point corner kick from Kerr.

Simon fired the first shot of the second stanza but just missed the target after some clever lead-up work from Kerr down the left wing.

Sydney continued to dominate general play but the dangerous combination of McDonald and Barilla almost stung the hosts in the 68th minute, with McLaren again on hand to save the day.

Davey diffused a dangerous situation at the other end moments later, just beating Simon to a loose ball on the edge of the penalty box.

Melbourne's Amy Jackson was denied by McLaren moments later as the end-to-end action kept coming.

But the Sydney custodian was powerless to stop Spiranovic's match-winner as the replacement striker swooped on a loose ball and connected from close range to stun the hosts.

Sydney FC 1 (Kennedy 41,)
Melbourne Victory 2 (Catley 8, Spiranovic 81)

Sydney FC: 1. Sian McLaren, 2. Teresa Polias, 3. Elizabeth Ralston, 4. Samantha Kerr, 9. Caitlin Foord, 10. Renee Rollason, 12. Chloe Logarzo (Annalie Longo 70), 13. Larissa Crummer (Hannah Bromley 82), 14. Alanna Kennedy (Nicola Bolger 65), 17. Kyah Simon (c), 19. Emma Kete
Melbourne Victory: 1. Brianna Davey, 2. Danielle Johnson, 3. Maika Ruyter-Hooley, 4. Rebekah Stott, 6. Petra Larsson, 7. Stephanie Catley (Cindy Lay 90), 9. Tiffany Eliadis (Fishlock 46), 10. Jessica McDonald, 14. Enza Barilla, 15. Amy Jackson, 17. Gulcan Koca (Laura Spiranovic 77)