Anthony Ogogo produced arguably the greatest performance of his career to defeat Ukraine's reigning world champion Ievgen Khytrov via a nail-biting judges' decision to move within one more win of a boxing medal.
Ogogo matched his illustrious opponent in a brutal, action-packed bout which had the capacity ExCeL crowd on their feet, then faced an agonising wait as the final score showed an 18-18 tie between the pair.
Even the countback system - in which the individual scores of all five judges are tallied together - yielded an amazing 52-52 tie, before the judges were required to pick a winner and the majority went with the Briton.
Even then the drama was not quite over, as Ukraine launched an appeal against the verdict, which was swiftly dismissed by AIBA's competition jury, who said they had "no special grounds" for the complaint.
Ogogo, who will next box Germany's Stefan Hartel with a bronze medal guaranteed for the winner, cited his mother's battle against a brain haemorrhage as his inspiration to pull off a result few believed he was capable of.
Ogogo said: "My mum made me the winner. After everything that has happened to me I could have crumbled in those last few seconds but that gave me the extra strength to get over the finish line. Nobody thought I would win that fight - I don't think even the rest of my team-mates thought I could win it - but I just believed in myself.
"I thought it was probably a countback and I've been on the wrong end of them so many times. With what's gone on with me in the build-up, I needed that. It's so much sweeter, and it's what got me over the finish line."