CREATE TABLE table_72064 ("Date" TEXT, "Time" TEXT, "Competition" TEXT, "Opponent" TEXT, "Ground" TEXT, "Score" TEXT)

What kind of competition was it at San Siro at 18:30 GMT?
SELECT "Competition" FROM table_72064 WHERE "Ground" = 'san siro' AND "Time" = '18:30 gmt'
SELECT "Competition" FROM "table_72064" WHERE "Ground" = 'san siro' AND "Time" = '18:30 gmt'