REFILE-'Iron Man 3' explodes with huge $175.3 mln in U.S., Canada debut
May 05, 2013 at 12:10 PM EDT
NEW YORK, May 5 (Reuters) - Superhero sequel "Iron Man 3" rocketed to the top of U.S. and Canadian box office charts, kicking off Hollywood's summer movie season with an estimated $175.3 million in weekend ticket sales for the second biggest opening of all time.