Superman Returns posted a mighty $21,015,000 in ticket sales on its opening day Wednesday, including midnight screenings the previous night, according to unofficial figures posted by the industry website Showbiz Data today (Thursday). Although well ahead of last year's $15.1-million opening of Batman Begins, the figure paled compared with the $40.5 million taken in during the July 2004 opening day of Spider-Man 2, which holds the record for the biggest box-office take for a Wednesday opener. It also ranks considerably below the Wednesday opening of The Lord Of The Rings: The Return of the King," which debuted with $34.5 million in December 2003.