Glory's marquee star lived up to her billing as she scored a brace and set up two others in the one sided affair.
Perth's attacking players had a field day against a disjointed City side with strikers Alyssa Mautz claiming a brace and Rachel Hill also finding the back of the net.
Elise Kellond-Knight scored both of city's goals but they proved to be mere consolation against the Kerr led Perth onslaught.
Kerr opened the scoring with a contender for goal of the season as she ran 50 metres slaloming through the Melbourne defence before unleashing a rasping shot into the back of the net.
It proved to set the tone for the rest of the contest with Hill, Mautz and Kerr unable to be stopped by a City side struggling to fight their way into the contest.
The result moves Perth to second on the W-League ladder with eight points from their first four matches.
Melbourne City remains rooted to the bottom end of the competition rankings in eight position with three points.
It doesn't get any easier for City next week as they take on third placed Adelaide United, while Perth Glory have a bye.