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_68578 ( "Res." text, "Record" text, "Opponent" text, "Method" text, "Event" text, "Round" text )

### Question ###
Which event is a win by an opponent of Nicolas Smith, with the round marked n/a?

### Accurate SQL ###

SELECT "Event" FROM table_68578 WHERE "Res." = 'win' AND "Round" = 'n/a' AND "Opponent" = 'nicolas smith'