CREATE TABLE table_name_18 (attendance NUMBER, league_position VARCHAR2, opponents VARCHAR2)

When in the 1st league position, how many people watch as they faced West Ham United?
SELECT MIN(attendance) FROM table_name_18 WHERE league_position = "1st" AND opponents = "west ham united"
SELECT MIN("attendance") FROM "table_name_18" WHERE "1st" = "league_position" AND "opponents" = "west ham united"