He became famous as a player for the UE Red Warriors team under Coach Baby Dalupan.

Mariano was the flag bearer of the Philippines at the 1972 Summer Olympics in Munich, Germany.

In 1990, he returned to Presto and led the team to the 1990 All-Filipino championship, his only PBA title.

[4] He also led the University of the East Red Warriors to two titles in the UAAP Championships in Season 47 and 48 (1985–1986).

By 2014, he is coaching the Cainta Catholic College high school varsity team.