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_56820 ( "Outcome" text, "Date" text, "Tournament" text, "Surface" text, "Opponent in the final" text, "Score in the final" text )

### Question ###
Who was the opponent on the 28 july 2013 final?

### Accurate SQL ###

SELECT "Opponent in the final" FROM table_56820 WHERE "Date" = '28 july 2013'