Star Wars: Episode III - Revenge of the Sith grossed $50,013,859 from showings at 3661 theatres and more than 9000 screens around the United States on Thursday, according to box-office tracker Exhibitor Relations.
That beat the one-day record set in May 2004 by Shrek 2, which sold $44.8 million on a single Saturday - its fourth day in theatres.
"It's staggering," said Bruce Snyder, president of domestic distribution at Twentieth Century Fox. "It's probably 20% more than I thought we could do."
The George Lucas film, which features the transformation of Jedi Knight Anakin Skywalker into the evil Darth Vader, also beat the opening day record held by Spider-Man 2, which grossed $40.4 million when it opened on a Wednesday last June.
"Fifty million is a good opening weekend, let alone a single day," said Paul Dergarabedian, president of Exhibitor Relations. "This is the box office equivalent of a 100-year flood."
The news comes as a relief to Hollywood, which has seen a box office slump for 12 straight weeks.
The Star Wars franchise has been
making film history since 1977
Theatre owners, studios and marketing partners had their hopes pinned on Star Wars, to kick-start the summer movie season and they were not disappointed.
The film debuted on 2900 screens at midnight on Thursday.
The take from that one showing alone was $16.5 million, which beat the previous record of $8 million set by The Lord of the Rings: The Return of the King, in 2003.
Thursday's take dwarfed the next highest film, and last week's box office champ, Monster-in-Law, starring Jane Fonda and Jennifer Lopez. That film grossed $1.5 million on Thursday, according to BoxOfficeMojo.com.
It is almost assured that Star Wars will push past the $100 million mark for its opening weekend.
The record for a three-day weekend is held by the first Spider-Man, which grossed $114.8 million in May 2002.