Newcastle are facing going from A-League champions to wooden spooners within a season after losing 2-1 at home to Sydney FC.
The champions have now gone six matches without a win, and sit at the bottom of the ladder eight points outside the top four with seven games to go.
Compounding Newcastle's woes was Perth's 3-1 upset win over Melbourne.
The Glory jumped off the bottom to go to `15 points, three ahead of the Jets .
Adelaide claimed top spot with 24 points after thumping the Wellington Phoenix 6-1.
That will give them plenty of confidence heading into Thursday night's FIFA Club World Cup quarter-final playoff against Waitakere United in Tokyo.
Melbourne are in second on 23 after their loss to Perth, while Sydney jumped three spots to be narrowly ahead of Queensland on goal difference after the Roar drew 1-1 with Central Coast.
The draw leaves the Mariners on 19 in fifth, a point behind Sydney and Queensland, and one ahead of the Phoenix.