Unsurprisingly, the boxing arena at Riocentro was a cauldron of noise, with Conceicao enjoying huge support. He had already knocked out Cuban top seed Lazaro Alvarez in the semi-finals, so expectations were high.
The 27-year-old from Salvador in northeastern Brazil was on top from the opening bell, and his every punch met with roars of approval from a capacity crowd.
Conceicao claimed the first two rounds on all three judges' scorecards, before Oumiha came back stronger in the third. However, by then, the momentum had already tipped inexorably towards the Brazilian.
As he stood on the podium with the gold around his neck, the crowd stood and sang the national anthem.
"Of course my life has changed, it is the most incredible day in my life,” said Conceicao. “This medal is not only for my coach but for myself and family... I'm Olympic champion! It was an amazing day.”
“Amazing” was also the word used by Conceicao’s beaten opponent, Oumiha. "It was amazing,” said the Frenchman, who enjoyed the intensity of the atmpsphere in the arena. “I was prepared for it and I spoke about it with my coach beforehand but what an experience!”
“It's the first time I've fought in front of a crowd like this but it was magnificent. The Brazilian public were so behind him. If it had been in France, it would have been the same for me.”
Brazil had previously hinted at a boxing renaissance by winning three medals at London 2012, but now in Conceicao, they have a first ever Olympic champion and a new hero.