By Patrick Johnston

LONDON (Reuters) - Brazilian Esquiva Falcao Florentino guaranteed Brazil their first men's boxing medal since 1968 with a dominant performance over Hungarian Zoltan Harcsa on Monday which suggested he could win more than just a bronze.

Florentino's 14-10 middleweight victory meant a semi-final place and only a second medal in men's boxing for the soccer-obsessed nation, who will host the Games in four years time.

"I'm very, very proud to be the first to guarantee a medal for Brazil here," Florentino told reporters through a translator. "I'm very proud because I told my dad (I) was going to take a medal home and now (I have)."

"I'm not here to win the bronze medal, I'm here to win the gold medal and I am confident I will get the gold."

The middleweight's medal came a matter of hours after his compatriot Adriana Araujo secured at least a bronze in the women's lightweight category by reaching the last four.

But Brazilian fans will be confident of more than that after Florentino easily produced the most eye-catching display of the four middleweights to advance to the semi-finals.

His lightning quick hand-speed had Harcsa worried and after the Hungarian felt the full force of some thunderous uppercuts he chose to stand back, wary of Florentino's power.

The Brazilian led 6-2 after the first round and fought within himself to edge over the line as he slowed down the pace of his attack and preferred to throw more considered shots.

He will next face Briton Anthony Ogogo for a place in the final after the home favorite took his bout against German Stefan Hartel.

Roared on by a passionate crowd at the ExCel arena in south east London, Ogogo was awarded the first round 5-2 despite the exchanges between the cagey pair looking even. The Polish judge gave the round 7-1 to the Briton.

Undeterred, Hartel continued to press and continually pushed Ogogo back with his strong jab but was restricted after sustaining an injury and the Briton came up with some fast combinations to take the victory.

"In the first round I damaged my right hand, it had already been broken before so that limited me," Hartel, who came into the media area shaking his wrist in pain, told reporters.

"I feel that because of the crowd supporting Ogogo, the judges may have favored Ogogo."

The Briton accepted he had taken some punishment from the German.

"I took a few rights hands so I might get a slap on the wrists tomorrow," Ogogo told reporters before looking ahead to his bout with Florentino.

"I'm boxing the Brazilian that beat me in the world championships but I've got two good arms now so I'm looking forward to doing battle with him," citing an injury as the reason he lost their previous encounter.

In the other semi-final Uzbek Abbos Atoev will face Japanese second seed Ryota Murata on Friday after they both scored 17-13 wins in their quarter-finals.

Murata produced a big 10-5 third round to come from behind and take his contest, while Atoev beat Vijender Singh, which left the Indian's corner complaining at what they felt was another wrong decision.

The Indian team are still reeling from the International Amateur Boxing Association (AIBA) decision to change the result of welterweight Vikas Krishan's victory to a defeat by American Errol Spence following a video review and were unhappy again.

"It's a mafia, mafia, mafia, no point complaining," India's Cuban boxing coach Blas Fernandez shouted as he walked to the dressing room.

(Additional reporting by Padraic Halpin; Editing by Greg Stutchbury)