Robson Conceicao said he felt like he was still dreaming after he became the first Brazilian to win Olympic boxing gold on Tuesday in front of an exhilarated Rio crowd.

The man who sold vegetables and ice cream on the streets as an impoverished child is now a national hero after defeating France's Sofiane Oumiha by unanimous decision in their thrilling lightweight final.

The 27-year-old, who said he once faked an arm injury so he could get hospital treatment and then used the bandages to tape his hands for boxing, was a deserving winner after another day of judging controversy.

"My life has changed with this, this is an incredible moment," Conceicao said.

"I had a very difficult upbringing, so this medal is not only a success for myself but a success for my family and all those people who took me to training, ever since I was a young boy.

"I am an Olympic champion so my life has changed forever. It was an amazing crowd ... an amazing day."

Brazil had only ever won one silver and three bronze boxing medals before Conceicao's heroics, and he said the title was a gift to his daughter, who will celebrate her second birthday on Friday.

"I will tell her that she was my biggest inspiration and that I wanted to give her the biggest gift that I could," he said.

'Incredible feeling'

Each punch Conceicao landed was greeted with huge cheers, against a backdrop of "You're gonna die!" chants aimed at the 21-year-old Frenchman.

It was the first time at the Games that the 9,000-capacity Rio Centro Pavilion was packed to the rafters.

The fighters engaged in a slugfest right from the opening bell, with Conceicao the busier of the two as they traded heavy hits.

Round two was closer, with Oumiha at times forcing the Brazilian behind a jackhammer jab.

Oumiha held the center of the ring in the third and held firm when the Brazilian invaded his space, but the Frenchman had difficulty landing clean punches behind Conceicao's steady guard.

Conceicao grew up fast, hawking his meagre wares with his grandmother in the northern city of Salvador, knocking on car windows to sell melting ice cream to the occupants.

He paid tribute to the raucous crowd and to the people back in his home state who raised him in the most trying of circumstances.

"It was an incredible feeling to represent the whole of Brazil," said Conceicao.

"Now I need to relax and wake up from this dream that I am experiencing and carry on boxing for the Brazilian national team and head to the next Olympics."

Bronze went to Cuba's Lazaro Alvarez - a semifinal victim of Conceicao's - and Otgondalai Dorjnyambuu of Mongolia.

Oumiha was largely an unknown quantity heading into Rio and admitted the Brazilian was the better man on the day.

Asked whether he felt more pride or disappointment at taking home silver, he replied: "A bit of both. But obviously as time goes on I'll realize my good fortune and I'm really proud of my silver medal and winning it for France."