The final chapter in the "Star Wars" movie saga grossed a record $50 million from its first 24 hours in North American theaters, the highest box office tally ever for a single day, 20th Century Fox said on Friday.

Nearly 30 years after George Lucas revolutionized cinema with his original sci-fi tale of good vs. evil in a galaxy far, far away, the concluding installment to his double trilogy seemed firmly on course to redefine the boundaries of the Hollywood blockbuster.

Opening Thursday on some 9,400 screens in nearly 3,700 U.S. and Canadian theaters, "Star Wars: Episode III -- Revenge of the Sith" generated $16.5 million in ticket sales from sold-out debut midnight showings packed with costumed fans and went on to accumulate $50,013,859 in receipts by day's end.

The unprecedented sum easily surpassed the previous opening-day box office record set last June by "Spider-Man 2" -- $40.4 million -- and the $44.8 million single-day benchmark "Shrek 2" grossed a year ago in its fourth day of release.

The film's huge first day cheered Hollywood executives eager for a hit that would shake the movie industry out of a 12-week box office slump.

"We've never seen anything this before," said Paul Dergarabedian, president of box office tracking service Exhibitor Relations. "This is an unprecedented achievement."

The film benefited from generally warm reviews compared with the two previous "Star Wars" prequels, as well as massive expectations generated by its status as the grand finale to Lucas' epic, revealing the secrets to such mythical questions as the origin of Darth Vader.

But Dergarabedian said much of the credit for the film's stunning commercial success belonged to a shrewd marketing strategy by producers, exhibitors and the studio.

"This was a true collaboration between Lucasfilm, theater owners and (20th Century) Fox," he told Reuters. "They made this happen. This was a carefully planned release, and everything worked perfectly."

At the very least, "Sith" appeared on track to eclipse the $110 million grossed by its immediate predecessor, "Episode II -- Attack of the Clones," through its first weekend three years ago and to swiftly recover the $113 million it cost to bring the "Episode III" to the screen.

"Clones," which also opened on a Thursday, grossed $30.1 million its first day. But the first prequel in the series, "Episode I -- Phantom Menace," so far stands as the biggest box office success in the franchise, grossing more than $922 million worldwide.

Collectively, the first five "Star Wars" films have grossed $1.8 billion in the United States and Canada and a total of $3.8 billion globally.

In addition to its North American release, the film is opening in 104 other countries through the weekend, but no overseas figures were immediately available from Fox, a unit of News Corp. Ltd.