Their high-octane approach saw them dominate early possession and territory without really testing former Phoenix goalkeeper Liam Reddy in the Perth goal.
By contrast, Perth lacked cohesion but slowly grew into the contest, fashioning the better openings before the break.
Castro was the game's most dangerous player, taking control midway through the first half and creating the majority of Glory's best moments.
Only a lack of quality in front of goal prevented Perth from taking what would have been a deserved halftime lead.
The breakthrough came early in the second half when debutant referee Daniel Elder awarded the first of two second-half penalties to the hosts. Castro and Andy Keogh combined beautifully down the left and when Keogh swung in a teasing ball, Adam Parkhouse was adjudged to have tripped striker Chris Harold as he sprinted to meet the cross. Castro made no mistake from the spot.
The second penalty came after an hour, when Keogh was brought down by Glen Moss as he attempted to round the Phoenix goalkeeper to convert a one-on-one opportunity.
The Irish striker took over the spot-kick duties but his tame effort was easily saved.
The respite was to be short-lived however with Glory doubling their lead shortly afterwards.
Fullback Josh Risdon stormed down the right before cutting a lovely pass into the path of Marinkovic who gleefully belted the ball into the roof of the net.
Roy Krishna had the chance to give the Phoenix a foothold with fifteen minutes left, but his close range header was beaten away by Reddy.
The Phoenix will need to regroup quickly ahead of their next assignment; a clash with red-hot league leaders Sydney FC in Wellington next Sunday evening.
Glory 2 (D Castro, N Marinkovic)
Phoenix 0
Ht: 0-0.
