Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_name_73 (tournament VARCHAR, opponent_in_the_final VARCHAR, surface VARCHAR)

### Question ###
Which tournament had Toshiaki Sakai as an opponent in the final on a grass surface?

### Accurate SQL ###

SELECT tournament FROM table_name_73 WHERE opponent_in_the_final = "toshiaki sakai" AND surface = "grass"