The first half was one-way traffic as Melbourne blew off any pent up frustration from their poor start to the season. Ball after ball was played straight through a Phoenix backline that must have grown wary of chasing shadows.
Respite arrived after Rojas' second sealed the points and the Phoenix finished the stronger side, easing some of the pain of the first 50 minutes.
The loss leaves the Phoenix in eighth place after five games and continues a run of futility against the Melbourne sides, having never won in 12 visits to Victoria.
The Victory's first chance was squandered when Archie Thompson misdirected his chip past the advancing Paston, but that was merely a sign of things to come as Melbourne picked apart the Phoenix defence with worrying ease.
A flat and high back four left plenty of space for Melbourne to exploit, while the roaming quartet of Rojas, Thompson, Marcos Flores and Gui Finkler were causing plenty of headaches by occupying the area between defence and midfield.
The goal was coming and, when it arrived it midway through the half, it was from an appropriate source. Thompson ran onto yet another through ball and squared across the face of goal for Rojas to slot in a simple chance.
For all Melbourne's dominance the Phoenix could have been level with 10 minutes left when the visitors gave the Victory a taste of their own medicine, but Brockie couldn't finish from a Manny Muscat through ball.
The score soon became much more indicative of the action after a goal made in South America. An intricate series of passes between Argentine Flores and Brazilian Finkler opened up the Phoenix defence and the move got the finish it deserved when Flores slotted the ball inside Paston's post.
Halftime couldn't have come soon enough for the Phoenix, but the second half began with much of the same. Leo Bertos was badly exposed at right back and Thompson, once again, showed great vision to lay on a second for Rojas.
The points were all but wrapped up the victory and both teams seemed to sense it. Melbourne eased off the accelerator, while Ricki Herbert's double substitution of Paul Ifill and Stein Huysegems was akin to a white flag.
Postecoglou responded by withdrawing some of his best, and that triggered the Phoenix's first spell of dominance A couple of close calls came and went, before Brockie curled in a a beautiful effort across the face of goal then doubled his Phoenix tally with an impressive free kick.
Melbourne Victory 3 (Rojas 23, 48, Flores 38)
Wellington Phoenix 2 (Brockie 80, 90)
HT: 2-0
