The Warriors led 6-nil close to half-time when debutant forward Ken Maumalo was sent off for striking Wyong captain Mitch Williams in the chest with a raised knee while running the ball.

The impact was heard around the ground, and there were concerns for the hooker's wellbeing.

Williams was replaced, but he stunned the home crowd to return in the second stanza and cross for what Wyong believes should have been the match-winning try.

With Wyong trailing 6-4, the Warriors fumbled a kick close to their line and Williams toed the ball through and claimed it in the in-goal. But the match officials ruled a knock-on.

The decision stunned fans and did nothing to calm the Roos, who had been frustrated by a string of decisions in the game.

The loss puts a dent in Wyong's semi-final hopes.

They remain in ninth position on the ladder.

■ Wyong will host eighth-placed Newcastle at Morry Breen Field, Kanwal, this Saturday at 3pm.