James Tedesco has scored with 32 seconds left to give NSW a stunning 26-20 victory in the State of Origin decider to defend their shield.

Scores were locked at 20-all in the final minute when Blake Ferguson tiptoed along the sideline, then found Tedesco for his second try of the night.

It came after Queensland forward Josh Papalii crossed in the 77th minute and debutant Ethan Lowe nailed a pressure conversion to level the game.