RIO DE JANEIRO: Brilliant Cuban light flyweight Joahnys Argilagos underlined his rich potential as he became the first boxer at the Rio Olympics into the semi-finals to guarantee at least a bronze medal. The 19-year-old Cuban prodigy and world champion had Kenya’s Peter Warui running around in circles on the way to a unanimous points decision. Argilagos displayed the full array of his electric footwork, at one point ducking a Warui haymaker, whose momentum took him tumbling into the ropes. The Cuban merely grinned back at his opponent and later delivered a sucker-punch while appearing to look in the opposite direction. Argilagos faces Colombian Yurberjen Martinez in the semis on Friday, after he defeated Samuel Carmona Heredia of Spain on a split points decision.