In front of the setting Perth sun, Sydney FC were too clinical for Perth Glory.
Lisa De Vanna struck first in her personal battle with Sam Kerr as two of the W-League's most recognisable faces, pushing Sydney FC ahead on the 20th minute.
Chloe Logarzo then doubled Sydney's lead on the 48th minute. Perth couldn't rustle up a response at Dorrien Gardens.
The win moves Sydney to second on the ladder, leapfrogging Newcastle Jets after their surprise loss to Adelaide United.
Meanwhile, Perth's finals hopes are looking precarious, an almost unthinkable conclusion to the season considering their forward talent.
Glory remain three points above Melbourne Victory in sixth, with three matches remaining in the regular season.