Wanneroo City and Joondalup City were knocked out of the competition.
Division 2 side Joondalup United had a terrific 3-2 win over former Premier League side Bunbury Force, which has been relegated to Division 1 this season.
Sorrento thrashed lower-ranked Division 1 side Swan United 6-0 away on Sunday. While less emphatic, ECU Joondalup had a convincing 3-0 triumph over Division 2 side Forrestfield United.
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READ NOWWanneroo lost 4-0 to Cockburn City, while Joondalup City went down 2-0 to the Stirling Lions.
National Premier Leagues WA action resumes this weekend with Sorrento at home taking on Stirling and ECU facing Bayswater away.