user: Question: Who is the Opponent in the final on 4 April 2011?
Columns: ['Date', 'Tournament', 'Surface', 'Opponent in the final', 'Score']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['2 June 2003', 'Surbiton , Great Britain', 'Grass', 'Wesley Moodie', '4–6, 7–6(2), 1–6']
SQL:

assistant: SELECT "Opponent in the final" FROM "Table" WHERE "Date" = '4 April 2011';