Sydney had an early opportunity to draw first blood when the ball from a corner kick swung across the face of goal, but none of the waiting players could reach the ball in time to guide it past the goalkeeper.
The home side began to find their feet by launching a number of attacking plays, which eventually resulted in a goal from Fabio Ferreira.
The midfielder charged down the right with the ball before curling a shot around keeper Vedran Janjetovic to take the lead at the Coopers Stadium.
Adelaide dominated the midfield as the first half progressed, but Sydney's best chance of the opening 45 minutes came when Alessandro del Piero moved into the box to pick out Richard Garcia, but the ball just bobbled past the forward.
Adelaide continued to dominate in the second half, but Sydney were given a slice of luck when the ball fell to Matt Thompson in the area, which allowed him to squeeze a shot which glided into the top right corner of the net.
Despite a late surge from Sydney, Bruce Djite wrapped up the game for Adelaide by scoring two minutes before the end of normal time to grab maximum points.