Anthony Ogogo fell to his knees in celebration after pulling off the most dramatic victory of his career against Ukrainian world champion Ievgen Khytrov to move within nine more minutes of an Olympic medal.
Ogogo got the edge in a three-round war with his imposing opponent in their last-16 middleweight bout, but only after the scores were locked together at 18-18 and even the countback - the accumulation of all five judges' totals - showed a 52-52 tie.
It was then down to the five judges to each pick an individual winner, and Ogogo could barely control his emotions when his name was announced as the winner to the roaring, 10,000-capacity ExCeL crowd.
Even then the drama was nowhere near 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."
Ogogo started superbly against a 23-year-old opponent regarded as one of the best in the business, peppering Khytrov with a quick combination and staying busier behind an impenetrable guard as his opponent pressed forward. Ogogo's sharper work gave him a two-point lead at the end of the first round.
The second belonged to Khytrov, as he came on stronger and landed two big rights that forced the Briton to take a standing count. Another right soon afterwards brought a second count, though Ogogo showed few signs of being in trouble.
Both fighters started the final round in blistering fashion, Ogogo landing a combination before being jolted by a right hand and replying with a wide looping left which brought the crowd back to its feet.