CREATE TABLE table_203_675 (id DECIMAL, "match" DECIMAL, "date" TEXT, "round" TEXT, "home/away" TEXT, "opponent team" TEXT, "score" TEXT, "scorers" TEXT)

who was the first team a.c milan played against in the uefa championship league ?
SELECT "opponent team" FROM table_203_675 ORDER BY "date" LIMIT 1
SELECT "opponent team" FROM "table_203_675" ORDER BY "date" NULLS FIRST LIMIT 1