And ECU Joondalup is also on a four-game winless streak, sitting in ninth place.
Sorrento salvaged a late draw against fifth-placed Cockburn City on Saturday.
They trailed 1-0 at the 80-minute mark, but equalised one minute into stoppage time at Dalmatinac Park. The Gulls have returned two losses and two draws from their last four encounters.
At ECU Joondalup Football Stadium, the Jacks took the lead midway through the first half, but conceded two goals after the break in a 2-1 loss to 10th-placed Subiaco.
ECU has lost three and drawn one of its last four matches.
The side faces Cockburn away on Saturday, while Sorrento plays Perth Glory at home.