South Korea's Han Soonchul has produced a shock in the lightweight class by defeating Vazgen Safaryants of Belarus on a countback.

Safaryants walked forward trying to utilise his power by throwing bombs, but Han boxed well at range, keeping the Belarusian at the end of his jab to take a 6-4 lead.

The Korean was less successful in the second as Safaryants began to find the target, levelling the scores at nine apiece.

The third round became a stand-off as both fighters probed for an opening, seemingly unwilling to take a risk of being picked off.

The bout was scored at 13-13, but the judges believed that Han had done enough to scrape a narrow victory.