The Wanderers went into the match without Shinji Ono (illness), Ante Covic (groin) and Jerome Polenz (suspension), but had little trouble dispatching a lifeless Perth side playing to keep their season alive.
It took the visitors just 12 minutes to grab the lead through Mateo Poljak, who shuffled around Glory defender Michael Thwaite and blasted the ball into the bottom right corner of the net.
Substitute Tomi Juric put the result beyond doubt in the 71st minute when he pounced on a massive blunder from Glory marquee defender William Gallas.
Western Sydney wingers Labinot Haliti and Kwabena Appiah dominated from the outset and created plenty of chances with their dashing runs.
Haliti had two chances in the space of three minutes midway through the first half to double Western Sydney’s advantage, while Appiah beat Glory youngster Riley Woodcock for pace on multiple occasions.
The sturdy Wanderers defence, led by Nikolai Topor-Stanley and Matthew Spiranovic, was rock solid throughout and nullified the influence of striker Shane Smeltz.
Perth’s best chance of the first half came in the 29th minute when Chris Harold misjudged a header on the edge of the six-yard box.
It was the seventh game in a row Glory has failed to score in the first half.
Glory skipper Jacob Burns started on the bench for the second week in a row, but was brought on after the break and appearing to provide missing from Kenny Lowe’s side in the first half.
Rostyn Griffiths almost equalised with a header from a corner in the 70th minute, but former Gold Coast goalkeeper Jerrad Tyson pulled off an amazing save.
Former French international Gallas was left red-faced when he missed the ball as he attempted to clear it from the 20-yard box, only for Juric to swoop and score Western Sydney’s second for the evening.
Adding to Perth’s wounds, Thwaite picked up his fifth yellow card of the season and will miss next weekend’s away trip to Brisbane.
The win was an excellent way for second-placed Western Sydney to kickstart a tough eight-week period that will see the club play 14 matches, including three away trips for the Asian Champions League.
Glory has not recorded a win in their past six outings and remains ninth on the table with 21 points as their finals hope fade quickly.
Perth Glory 0
Western Sydney Wanderers 2 (Poljak 12', Juric 71')
Crowd: 8,543 @ nib Stadium
