The men's Olympic boxing competition drew to a dramatic close as Britain's Anthony Joshua put in a stunning final round to defeat reigning super heavyweight champion Roberto Cammarelle of Italy on countback.
Cammarelle subsequently lodged a protest but there was no change in the result, giving Britain only its second gold medal in the 91+kg category after Audley Harrison won gold at Sydney 2000.
Vasyl Lomachenko of Ukraine secured his second consecutive Olympic gold with victory over South Korea's Han Soon-chul in the 60kg lightweight category while Serik Sapiyev outclassed Britain's Freddie Evans to give Kazakhstan its third straight gold at welterweight.
Teenager Robeisy Ramirez Carrazana gave Cuba its second boxing gold of London 2012, defeating Mongolia's Tugstsogt Nyambayar in the 52kg flyweight final.
Beijing 2008 champion Cammarelle looked to have secured victory against Joshua after winning the opening two rounds to hold a three-point lead going into the final round.
However, Joshua was not to be denied and cheered on by a 10,000-strong crowd, the 22-year-old Briton won the final round to level the fight on 15-15 and take gold on countback after a nervous few minutes awaiting the outcome of Cammarelle's protest.
"The third round is always a good round. I'm a warrior. I watch Leonidas from Spartans all the time before I fight and one thing I learned is never give up," said the 22-year-old.
Cammerelle, meanwhile, could not hide his disappointment at having gold snatched from his grasp in the final round.
"I feel I've lost even though I got a silver medal to go along with the gold in Beijing and the bronze in Athens," said the Italian.
"But I feel it was an unfair score because I was winning."
Considered one of the best men's boxers at the Games, Lomachenko proved too strong for Han, winning the lightweight final 19-9 on points.
Two-time light welterweight world champion Sapiyev outclassed Evans to give Kazakhstan its third straight gold at welterweight.
Kazakhstan narrowly missed out on another gold when Russia's Egor Mekhontcev won the 81kg light heavyweight final against Adilbek Niyazymbetov by judges' preference after the fight ended level on points and the boxers could not be separated on countback.
Rising boxing talent Carrazana was made to fight all the way in his 53kg fight against Mongolia's Tugstsogt Nyambayar before eventually prevailing 17-14 in the 52kg flyweight final.