user: Question: Who was the opposing team during the game in Zagreb?
Columns: ['Date', 'City', 'Opponent', 'Results¹', 'Type of game']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['March 31', 'Bruxelles , Belgium', 'Belgium', '1:0', "Euro '64 Qualifying"]
SQL:

assistant: SELECT "Opponent" FROM "Table" WHERE "City" = 'Zagreb';