Based on the fairy tales Jack the Giant Killer and Jack and the Beanstalk, Jack the Giant Slayer stars Nicholas Hoult as the young farmhand Jack, who accidentally opens a gateway between the kingdom and the world of the Giants.
Jack and the Giant Slayer, also starring Ewan McGregor, Stanley Tucci and Bill Nighy, knocked down last weekend's number one movie Identity Thief to second place.
The Jason Bateman and Melissa McCarthy comedy earned $9.7m, adding to its total earnings of $107m.
Two more new releases also made it to the top ten list - 21 and Over with $9m and The Last Exorcism Part II with $8m.
A Good Day to Die Hard, the latest instalment of the Die Hard franchise, slipped from five to nine with $4.5m. Its total earnings are now $59.6m.
The Bruce Willis action film debuted at the top spot when it was released three weeks ago, earning $25m.
Silver Linings Playbook remains the only award-winning film on the list. It took in $5.9m, which puts its total earnings at $115m.
The film's star Jennifer Lawrence won the 'Best Actress' Oscar at the 85th Academy Awards last month.
Snitch, Escape From Planet Earth, Safe Haven and Dark Skies round out the top ten.
The top ten in full (studio estimates):
1. (-) Jack the Giant Slayer - $28 million
2. (1) Identity Thief - $9.7 million
3. (-) 21 and Over - $9 million
4. (-) The Last Exorcism Part II - $8 million
5. (2) Snitch - $7.7 million
6. (3) Escape From Planet Earth - $6.7 million
7. (4) Safe Haven - $6.3 million
8. (7) Silver Linings Playbook - $5.9 million
9. (5) A Good Day to Die Hard - $4.5 million
10. (6) Dark Skies - $3.5 million
Watch a trailer for Jack the Giant Slayer below: