Rihanna's movie debut, which is inspired by the classic Hasbro board game, pulls in more than £3.7 million to secure the number one spot ahead of James Cameron's 3D re-release of Titanic.
Joss Whedon and Drew Goddard's The Cabin in the Woods, the long-delayed horror movie starring Chris Hemsworth, debuts at number three with £1.6 million from 414 locations.
The Hunger Games falls from second spot to number four, while Aardman's The Pirates! In an Adventure with Scientists rounds out the top five.
Snow White tale Mirror Mirror, starring Lily Collins and Julia Roberts, slips three places to occupy the number six spot ahead of 21 Jump Street and Wrath of the Titans.
The UK box office top ten in full:
1. (-) Battleship - £3,763,348
2. (1) Titanic - £1,809,737
3. (-) The Cabin in the Woods - £1,601,161
4. (2) The Hunger Games - £1,494,174
5. (4) The Pirates! In an Adventure with Scientists - £1,477,517
6. (3) Mirror Mirror - £913,134
7. (6) 21 Jump Street - £528,122
8. (5) Wrath of the Titans - £495,768
9. (8) The Best Exotic Marigold Hotel - £273,338
10. (9) StreetDance 2 - £220,087
Watch the trailer for Battleship below: