City outclassed their crosstown rivals, picking them off at will, in a display that sent a chilling statement of intent to the entire league.

It was just City's second win at Etihad Stadium, the only other triumph was a 2-1 win under former coach John Aloisi.

Cahill launched the goal glut with an audacious curling long-range effort on 27 minutes that wowed the crowd of 43,188.

Last year's golden boot, Bruno Fornaroli doubled City's lead (31') ahead of the break before Luke Brattan (52') chipped in with a well deserved goal of his own after feeding the attack.

New Zealand international Marco Rojas scored on 62 minutes to give Kevin Muscat's men the faint hope of a fightback before Fernando Brandan completed the rout a minute later. 

City coach John van’t Schip played Neil Kilkenny in an unfamiliar full-back role and it paid dividends with Cahill and Nico Colazo and Luke Brattan holding it sturdily in midfield.

The game started off with players going at each other’s throats, and while second-choice goalkeeper Dean Bouzanis looked nervous from back passes, no clear cut chances were created by either team after 25 minutes.

The main talking point of the night will be Cahill’s opener, who stunned the Victory fans with a half volley from 40 metres out managed to fly over Lawrence Thomas’ head and into the net after the 27th minute.

The goal caused a momentum shift City’s way, Victory struggled to regroup after conceding the goal and four minutes later Victory’s poor marking in the box allowed third marquee Colazo’s cross to find Bruno Fornaroli who doubled the lead from close range.

On the brink of half-time Colazo had a free kick which had Lawrence Thomas diving to his right to palm it out for a corner.

And after the break City continued what they started, at the 52nd minute Bruce Kamau staked his claim after shrugging off Spaniard Alan Baro whose cut in managed to find Luke Brattan who tucked it away.

At 3-0 Marco Rojas’ return to Victory was the only positive for Victory tonight after playing his way through the City defence to pull one back.

Two minutes later City made sure there was no comeback on the cards after Argentine Fernando Brandan shrugged off Jason Geria to eventually make it 4-1.

Cahill’s nights work was done at the 66th minute when he was substituted for Anthony Caceres leading to a standing ovation from the City fans.

With 15 minutes remaining it looked like the result was beyond all doubt as Victory coach Kevin Muscat sent out 16-year-old Seb Pasquali for the ineffective Fahid Ben Khalfallah.

At the 90th minute Victory looked hopeful of a consolation goal after Leigh Broxham nearly chipped Bouzanis only to go over the crossbar.

Nick Fitzgerald almost made it five with the last kick of the game forcing a stop by Thomas and at full-time it finished 4-1 to City as they take maximum points from their first two games.

City now head back to AAMI Park for their first home game of the season against Perth Glory, while Victory travel to Adelaide to face the reigning champions at Coopers Stadium.

Victory now face the daunting prospect of facing off against City again in the semi-final of the FFA Cup on October 25.