Britain's Anthony Joshua has won a gold medal in the men's super heavyweight division.
The 22-year-old Londoner beat Italy's Roberto Cammarelle on countback after the scores were level at 18-18.
He trailed 13-10 entering the third round, but landed several big shots and managed to pull himself level.
Although the judges scored the fight even, Joshua won on the countback tiebreaker which evaluates larger parts of their total scores.
His victory in front of an ecstatic crowd at the ExCeL arena takes Team GB's gold medal tally at the Games to 29 - its biggest haul since 1908.
It was also the boxing team's third gold at London 2012, joining bantamweight Luke Campbell and women's flyweight Nicola Adams.
Earlier Welshman Fred Evans was beaten in his welterwight final and had to make do with silver.