Youngsters Luke Duzel and Seb Pasquali lined up in midfield.
A combination of experience and youth occupied the front third, with Alessandro Diamanti and Iker Guarrotxena sitting behind Lachie Wales who led the line.
United had the opening chances of the game via strikes from Diamanti and Pasquali.
Diamanti’s well-timed volley was saved by Victory keeper Matt Acton, before the ball fell to Pasquali who went inches from scoring with his shot from outside the area.
Victory punished United at the other end just a couple of minutes later through a classy Jake Brimmer goal.
Brimmer gave United keeper Ryan Scott no chance with a well-struck volley on the edge of the area.
The lead was doubled when Rudy Gestede found the back of the net for his fourth goal of the season.
Adama Traore’s pinpoint cross found Gestede whose outstretched leg made enough contact to place the ball in the bottom right corner.
It was three just after the half-hour mark when Ben Folami waltzed past Tomoki Imai before teeing up Elvis Kamsoba for a tap-in.
Folami was involved again in the 35th minute to add a fourth for Victory.
The winger found space on the left-hand side, cut onto his right foot before finishing past Scott.
United pulled one back just before the break after being awarded a penalty for handball.
Diamanti tucked the spot-kick away for his first goal of the season.
Things got worse for United early in the second half when Kamsoba nabbed his brace and Victory’s fifth.
Kamsoba played a one-two with Callum McManaman in the area and with plenty of time and space placed the ball in the back of the net.
Jacob Butterfield added a sixth 10 minutes from time, firing his shot into the top corner.
Western United 1 (Diamanti 45’)
Melbourne Victory 6 (Brimmer 12’, Gestede 22’, Kamsoba 33’ 50’, Folami 36’, Butterfield 82’)