Shakur Stevenson won by virtue of a first round knock-out today ©USA Boxing

Some of the world's best boxers rose to the fore on the fifth day of the International Boxing Association (AIBA) American Olympic Qualification Event in Buenos Aires today, including United States' rising talent Shakur Stevenson.

The 18-year-old Nanjing 2014 Youth Olympic gold medal winner produced another superb performance to knock-out Uruguay's Mathias Bagnado in the first round of their under 56 kilogram bantamweight quarter-final. 

“I got in there, started establishing my game-plan of hit-and-not-get-hit, and then I landed a right hook," Stevenson said afterwards.

"I am naturally right-handed but I fight southpaw, but I landed my right hand and he went out.

"It did not feel that hard but I knew I connected clean.

"The plan was to box him, keep him on the outside and don’t let him come in, then that knock-out happened out of nowhere, that is my first pure knock-out."

If Stevenson has been the outstanding individual star of the qualification tournament, then Argentina's fellow bantamweight Alberto Melián has provided the home highlights.

Alberto Melián (right) pictured in action at the 2011 Pan American Games in Guadalajara, was another winner today ©AIBA
Alberto Melián (right) pictured in action at the 2011 Pan American Games in Guadalajara, was another winner today ©AIBA

Melián followed his victory over Olympic champion Robeisy Ramirez by beating Mexican World Series of Boxing (WSB) star Sergio Alfredo Chirino in another close points encounter.

The dominant duo are joined by Puerto Rico’s Carlos Caraballo and Venezuela’s Jose Diaz in the semi-finals.

A good day for Puerto Rico continued with victory for Danielito Zorrilla in the light-welterweight under 64kg division after he overcame home favourite Ronan Sanchez.

Bahamas’ Rashield Williams scored a surprise win over Trinidad and Tobago’s Aaron Hassette to join him in the last four. 

Other winners today included Cuba's Pan American Games under 91kg heavyweight champion Erislandy Savon, who edged a split decision against Ecuador’s WSB boxer Julio Cesar Castill, while his fellow Cuban Leinier Pero was too strong for Brazil’s Rafael Duarte Lima in the over 91kg super heavyweight competition. 

Twenty quarter-finals also took place at the AIBA African Olympic Qualification Event in Yaoundé.

In the men’s under 51kg flyweight competition, Algerian top seed Mohamed Flissi outclassed Nigeria’s Muyideen Oyakojo to underline his title credentials.

His main rival appears to be Lesotho’s Moroke Mokhotho, who overcame Tunisia’s African Military Champion Montassar El Bouali in one of the bouts of the day.