Table schema:
CREATE TABLE table_name_50 (opponents VARCHAR, kick_off VARCHAR, h___a VARCHAR, referee VARCHAR)

Question: Who is the opponent of the match with a H/A of h, Beguiristain Iceta as the referee, and a kick off at 1993-04-18 17:00?
SQL: SELECT opponents FROM table_name_50 WHERE h___a = "h" AND referee = "beguiristain iceta" AND kick_off = "1993-04-18 17:00"