In late August of 1973, he travelled to Tokyo, Japan to challenge world Heavyweight champion George Foreman, losing by a knockout in the first round there on September 1st. Roman's corner protested that he was hit by Foreman while laying on the floor; which would have given Roman the world Heavyweight title by a disqualification if proven to be truth, but the WBA and WBC did not listen to his corner's complaints. Even thru he lost, the moment he stepped into the ring that night he made history by becoming the first Puerto Rican to challenge for the world's Heavyweight championsip, setting a path for Puerto Rican fighters in that division that so far has only been walked by Ossie Ocasio and John Ruiz after him. Ruiz later became the first Hispanic ever to be world Heavyweight champion.
Roman retired in 1981 with a record of 53 wins, 24 losses and 3 draws, with 26 knockout wins.
After his retirement, he became a favorite subject of the Whatever happened to...? question in Puerto Rico.