The Sky Blues scored twice more before half-time - and added a further three goals in the second stanza - to confirm a scarcely-believable 6-1 win to humble the team that knocked them out of last year's semis and book a place in Sunday's championship decider against Perth Glory at Optus Stadium.

After a week in which Liverpool and Tottenham Hotspur pulled off European miracles, and an epic penalty shootout in the west saw Perth and Adelaide get in on the act, it turned out the only thing the football gods had left to give was a bloodbath.

There's usually dramatic twists and turns whenever these two teams clash, especially in the finals. But the shock at the end of the 50th Big Blue was that there was no shock - Sydney FC were just way too good and Melbourne Victory were diabolical, succumbing to their worst finals loss ever and heaviest defeat in this fixture.

For the Sky Blues, it was a perfect night on a perfect pitch at Netstrata Jubilee Stadium in front of a heaving crowd of 12,141 - although the hundreds who were queued outside at the start missed the opening minutes and the first goal.

It came from Sydney's third corner in a row, with Brandon O'Neill's delivery curling its way right underneath the crossbar. Aaron Calver stood underneath the ball and in front of Thomas, who could not get proper purchase as he jumped over the Western United-bound defender to grab it. It slid from his grasp and trickled off Calver and over the line.

It was pure disaster for the visitors, who began to probe for a goal of their own to set things straight. Whenever they got Keisuke Honda involved, or managed to find the lively Elvis Kamsoba with space to roam into, they looked dangerous, and in open play, they looked the better side.

Victory's best chance of the half came in the 29th minute, when Honda slid a neat ball through to an unmarked Ola Toivonen in the box. The Swede uncharacteristically scuffed his shot, letting Sydney off the hook.

They would be brutally punished, with the hosts squeezing in a two-goal flurry before half-time. It was Grant once again who started the build-up to the first goal with a tantalising cross from the right, which picked out Le Fondre.

The Englishman's swipe at the ball was blocked, but the rebound fell beautifully for skipper Alex Brosque to slap it home with a sweet left-footed volley.

Then, a few minutes later, Siem de Jong sent in another cross from a similar area. Leigh Broxham got to it before any Sydney players could, with his attempt at heading the ball clear instead finding the back of the net.

A shellshocked Victory tried what they could in the second half but it was futile. Georg Niedermeier hacked down Le Fondre in the 63rd minute, giving away a clear penalty which was calmly converted. Le Fondre was back at it five minutes later, completing a snap counter-attack and sealing a quickfire brace.

Milos Ninkovic added the sixth, two minutes from time, belting home a deflected cross that fell to him at the back post. The only blemish was what happened in injury time - Toivonen headed in a Honda cross to score the very definition of a consolation goal.

SYDNEY FC 6 (Aaron Calver 3m, Alex Brosque 43m, Leigh Broxham 45+2m og, Adam Le Fondre 63m pen, 68m, Milos Ninkovic 88m) bt MELBOURNE VICTORY 1 (Ola Toivonen 90+1m) at Netstrata Jubilee Stadium. Crowd: 12,141. Referee: Chris Beath.