user: Question: Who has the first leg that has a round in the Semi-final?
Columns: ['Round', 'Opposition', 'First leg', 'Second leg', 'Aggregate score']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['1st', 'Lyon', '3–4 (a)', '3–0 (h)', '6–4']
SQL:

assistant: SELECT "First leg" FROM "Table" WHERE "Round" = 'Semi-final';