It's being called one of the biggest second-half fightbacks in NSW Cup history.

And it was hooker Mitch Williams - a surprise late inclusion - who spearheaded the win.

Williams was expected to miss the remainder of the season with an elbow injury.

But the resilient livewire was back to his best.

He scored a try and created several others in another master class in dummy-half play.

The win moves Wyong into eighth spot on the ladder.

Wyong will seal a semi-final berth if they defeat Wests Tigers at Campbelltown on Saturday in the final round.