user: Question: What is the race winer of the Portuguese Grand Prix?
Columns: ['Rnd', 'Race', 'Date', 'Location', 'Pole Position', 'Fastest Lap', 'Race Winner', 'Constructor', 'Report']
Types: ['real', 'text', 'text', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: [1.0, 'Brazilian Grand Prix', '23 March', 'Jacarepaguá', 'Ayrton Senna', 'Nelson Piquet', 'Nelson Piquet', 'Williams - Honda', 'Report']
SQL:

assistant: SELECT "Race Winner" FROM "Table" WHERE "Race" = 'Portuguese Grand Prix';