Fred Evans had to wait until the early hours to discover he had earned a nail-biting countback win over Canada's Custio Clayton as Great Britain matched their post-War record of five boxing medals at one Olympic Games.
Evans joined team-mates Luke Campbell, Anthony Ogogo, Anthony Joshua and Nicola Adams in earning at least bronze - matching the total from the 1956 Melbourne Games with Thomas Stalker's medal quest still to come.
But Evans' passage to the guaranteed medal stages was not rubber-stamped until 01.30 on Wednesday morning after a Canadian appeal on the grounds that the Welshman should have been deducted points for persistent warnings. Press Association Sport understands the appeal was rejected.
Earlier, there was heartbreak for Evans' fellow Welshman Andrew Selby, whose quest to join the medal rush came to an end as he was outclassed 16-11 by Cuba's Robeisy Ramirez Carrazana in the flyweight division.
Evans almost went the same way, blowing a five-point lead at the end of a superb first round as he switched off entirely in the second and allowed the Canadian back in the welterweight bout to the extent that he clawed back for a 14-14 draw.
Evans, who was unaware of the appeal, said: "I was really comfortable at the end of the first but perhaps I stepped off the gas a little. I didn't realise how much he pulled it back. In the last 30 seconds I started cruising because I thought I was three or four up."
Great Britain still have some way to go to match the achievements of Melbourne, when both Terry Spinks and Dick McTaggart won gold medals.
Evans had looked set for a comfortable night against the little-known Canadian, easing into a 7-2 lead, but he lost his focus in second and a big right from Clayton ought to have presented a timely reminder of his need to hit back.
The Canadian finished the round well, though a score of 6-3 in his favour was certainly a surprise, and Evans suddenly seemed caught in two minds as Clayton came back to force a tense and ultimately drawn-out finale.