How it started....
Ateneo and La Salle were co-founders of the NCAA but now compete in the UAAP. The seed for a future rivalry was planted after an Ateneo loss to La Salle in the championship game of NCAA season 16 (1939–40). Games between Ateneo and La Salle in the NCAA were always hotly contested but not yet tagged by the sportswriters as a rivalry since the recognized rivalry then was between Ateneo and San Beda. When Ateneo and La Salle transferred to the UAAP, they continued their hotly contested games and the sports press started to write about a rivalry.
These games draw huge crowds of students, school faculty/ officials, alums, high government officials such as cabinet members, senators and even a chief justice of the Supreme Court. Former presidents of the Philippines and ambassadors of the United States of America also attend the games. Both schools have extended their rivalry into the academic field and other sports.