BRYCE Gibbs' bungled shot on goal at the end of Carlton's stirring victory over Hawthorn was disallowed shortly after the final siren on Saturday night, reducing the Blues' winning margin from eight to seven points.

Gibbs appeared to have blown a near-certain goal when he dropped a relatively easy mark while unopposed deep inside Carlton's forward 50, and then hit the post from almost point-blank range.

The midfielder's behind was initially allowed to stand, taking Carlton's final score to 12.6 (78) against the Hawks' 10.10 (70).

However, later on Saturday night the Blues' score was reduced to 77 points.

An AFL spokesman confirmed on Monday morning Gibbs' behind was disallowed shortly after the final siren. 

"It was changed a few moments after the match once the umpires consulted, because the kick was after the siren. As I understand it, it was done before the umpires left the field," he said.