The Jacks took first blood via Jon Stynes and held the Gulls at bay for the majority of the half at ECU Joondalup Football Stadium.
Sorrento managed to draw even just before the end of the first half thanks to an impressive free kick from Reece Vittiglia.
The Gulls stepped up their attack after the main break to hit the front just four minutes in courtesy of Brodie Martin.
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READ NOWMartin capitalised on a sharp pass from Daryl Platten and lack of concentration from ECU.
The Jacks could not find an equaliser, with Sorrento’s Todd Harnwell putting the final nail in the coffin at 89 minutes.
Gulls coach Jamie Harnwell told WA NPL media it was a big three points to win over their arch rivals.
‘ECU, as a club, are like our younger brothers. The rivalry is certainly real, it’s always a big game every time we play them,’ he said.
Sorrento faces Bayswater at home, while ECU takes on league leader Bayswater away on Saturday.