user: Question: Who did Thomaz Bellucci play against when he became Runner-up on a Clay surface?
Columns: ['Outcome', 'Date', 'Tournament', 'Surface', 'Opponent', 'Score']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Runner-up', '14 February 2009', 'Brasil Open , Costa do Sauípe, Brazil', 'Clay', 'Tommy Robredo', '3–6, 6–3, 4–6']
SQL:

assistant: SELECT "Opponent" FROM "Table" WHERE "Outcome" = 'Runner-up' AND "Surface" = 'Clay';