© Getty Images
Inside the first minute of the game Nebojsa Marinkovic tried to give Perth an early breakthrough when he attempted to curl a shot past the goalkeeper, but his effort went wide.
Minutes later, early substitute Romeo Castelen tried his luck for Western Sydney with a 20-yard shot, but his attempt flew just over the crossbar.
As the first half progressed, it became a tactical battle, with both sides creating opportunities but neither being able to make the most of them.
After the break, the visitors showed some skill in their build-up play before the ball was picked up by Marinkovic, who went for glory, but sliced his shot.
In the 62nd minute, Western Sydney took the lead after breaking swiftly from a corner kick. Castelen was on the ball and he managed to cut inside before hammering the ball into the far corner from 15 yards out.
Andy Keogh stepped up to take it and he showed composure by slotting the ball past Liam Reddy and into the right corner.
Not long after equalising, Perth squandered an opportunity to take the lead when Harold, who met the end of Diego Castro's cross, missed the target with a free header from six yards out.
The winner came in the 85th minute and it went to Western Sydney as Brendon Santalab connected with a high ball and looped it into the back of the net.
Western Sydney now have a three-point lead in the ladder.body check tags ::