The Gulls’ 5-0 loss to Balcatta dropped them to fourth on the table ahead of a must-win clash against Inglewood.
ECU Joondalup’s 3-1 win over Cockburn City has it in seventh and four points off a top five spot as it heads into a clash with Perth.
The Gulls were 1-0 down at half-time but the flood gates opened in the second half as the home side piled on four goals.
Sorrento coach Jamie Harnwell rued the effort of his side.
At Dalmantinac Park, a two-goal display from ECU Joondalup’s Danny Dixon had the away side 2-0 up against Cockburn City by the ninth minute of the match. The Cockerels snatched one back early in the second half but ECU quickly responded.