Sanfilippo began his career at San Lorenzo in 1953, he set a remarkable record of being the topscorer in the Argentine league four seasons in a row between 1958 and 1961 for San Lorenzo. This achievement has yet to be surpassed.
Whilst playing for his club San Lorenzo in a friendly match against Coventry City in 1956 at Highfield Road, he was sent off by referee Arthur Ellis in the 1st half with the score at 1-1. He refused to leave the pitch with some of his teammates trying to drag him off and Ellis abandoned the match.
In 1963 he moved to Boca Juniors, he was the topscorer in the Copa Libertadores with seven goals in seven games, but Boca were beaten in the final by Brazilian team Santos Futebol Clube. Sanfilippo played 27 games for Boca in all competitions, scoring 14 goals.
Sanfilippo then had spells with Nacional in Uruguay, Banfield back in Argentina, and Brazilian clubs Bangu and SC Bahia.
In 1972 Sanfilippo returned to San Lorenzo and took his place in the back to back championship squad that won the Metropolitano and the Nacional championships. At the end of the year he retired from football. At 1978, he played in the Club Atlético San Miguel, of the 4th. Division.
By the end of his career in Argentine football Sanfillipo had scored 226 goals in 330 games, making him the 5th highest scoring player in the history of the Argentine Primera.
After retirenment he became famous as an extremely polemic football analyst, having quarrels with many famous players .