The top seed outpointed his opponent, winning all three rounds unanimously to ensure that his country has now won gold medals in all 12 weight categories to have featured at the Olympics.

Fighting out of the red corner, La Cruz won the first two rounds on every judge's scorecard.

He was on the wrong end of the verdict in the third as Niyazymbetov made more of an impact but La Cruz knew he had done enough to secure Cuba’s first boxing title of Rio 2016, barring a knockout.

"I am very happy I got the gold," La Cruz, beaten in the quarter-finals at London 2012, said. 

"Thanks for the support.

"I am thankful to my family and all the people who made this possible and I owe it to them."

Niyazymbetov was bitterly disappointed to win the silver medal again, after also falling at the final hurdle at London 2012, when he was beaten by Russia's Egor Mekhontsev.

He had been hoping to become the second Kazakh boxing champion of the tournament after Daniyar Yeleussinov won welterweight gold yesterday.

Niyazymbetov said he believed he had won the fight against La Cruz but had to respect the decision of the judges.

"When you've won the silver medal for the second time, it can be a bit emotional," he said.

"I've been training for four years, preparing myself for the gold medal and now I've got a silver medal which is also good but now I think my feelings are much stronger, more emotional than when I won silver at the London Olympics."

France's Mathieu Bauderlique and Great Britain's Joshua Buatsi took the bronze medals as losing semi-finalists.

Bauderlique lost against La Cruz in the last four on Tuesday (August 16) after which Niyazymbetov got the better of Buatsi.

The first gold medal of the women's tournament will be awarded in the lightweight category tomorrow as world champion Estelle Mossely of France takes on China’s Yin Junhua.