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_28211674_3 ( mixed_veteran VARCHAR, womens_singles VARCHAR, mens_singles VARCHAR )

### Question ###
When Naomi Owen won the Womens Singles and Ricardo Walther won the Mens Singles, who won the mixed veteran?

### Accurate SQL ###

SELECT mixed_veteran FROM table_28211674_3 WHERE womens_singles = "Naomi Owen" AND mens_singles = "Ricardo Walther"