Russia's Arsen Galstyan claimed the men's under 60kg extra-lightweight judo gold
with victory over Japan's Hiroaki Hiraoka in just 31 seconds.
Galstyan managed to turn his opponent and pinned Hiraoka for what was originally given as a waza-ari score.
However, after the Russian's coach argued, the decision was reviewed and changed to a winning ippon score.
Britain's Ashley McKenzie suffered an
early exit from the competition
when he was beaten by Hiraoka.
McKenzie started brightly in his first Olympic contest but the number two seed and two-time World Championship silver medallist ended the bout with 50 seconds remaining by pinning the British judoka to achieve an ippon score.
Hiraoka overcame Elio Verde in his semi-final, the Italian then losing his bronze-medal contest to Brazil's Felipe Kitadai.
Galstyan had beaten number one seed Rishod Sobirov in his semi-final, with the Uzbekistan judoka winning his bronze-medal match against France's Sofiane Milous.