China's Jia Zhanbo won the gold medal in the men's 50-metre rifle three-position target event at the Athens Olympics on Sunday after American Matthew Emmons was ruled to have fired at the wrong target on the verge of victory.

Emmons was an almost uncatchable three points ahead as he took his very last shot but got an extraordinary score of zero with the final bullet and dropped out of contention.

There was initial confusion, with a puzzled Emmons checking his rifle, before the judges concluded he had fired at the target of the Austrian shooting in the lane to his right.

Although it could not be immediately confirmed, Emmons may have inadvertently helped Christian Planer to the bronze medal with his wayward last shot. The Austrian had been in fifth position when he was credited with a final-shot bullseye.

That was Planer's best scoring shot of the final round, worth 10.6 points, and catapulted him up to third place.

Emmons was dropped from first to eighth place with the zero in the final round.

Michael Anti of the United States moved up to second place to win the silver medal.

Emmons had won the gold in the 50-metre prone position event on Friday.