All six goals were scored in a volatile opening half which saw Eric Bauthéac red carded in the 21st minute.
Roar were already down a goal when the Frenchman was marched and under the circumstances did well to keep a lid on the final result.
But a brace to Kosta Barbarouses (13', 45+2'), a goal by Ola Toivonen (32') followed by a Keisuke Honda penalty eight minutes later, did the damage and sent Victory to the top of the table with Perth Glory still to play.
A sublime pass from Troisi set up Barbarouses for the opener against the run of play but the Socceroo wasn't getting ahead of himself.
"To be honest we’re a little bit disappointed with the goals we conceded whether they were free kicks or penalties or whatever we’ve got to defend them better and not make excuses," he told Fox Sports post-match.
"But away from home, we keep the ball rolling, we’re consistent this season and that’s the most important thing."
Down a man, Roar equalised through an Adam Taggart penalty (27') before Toivonen made the scoreline even more respectable for the home side with a headed own goal.
"The game got out of hand a little bit which was disappointing to see," Troisi said of the first 45.
"That’s what we said at half time, stay focused, keep doing what we’re doing and you know... it was (about being) less erratic, more structured.
"We created a couple of chances (in the second half) but like I said four goals away from home you can’t complain too much.
"We’re staying focused, we’re not getting carried away. Like I said we’ll be disappointed with tonight and we win 4-2 away from home. That’s the mentality we’ve got to have – never be satisfied and that will leave us in good stead."