Despite experiencing a 50% drop in ticket sales, the £3 million haul of Ridley Scott's return to science fiction is enough to see off competition from fellow blockbusters Men in Black III and Snow White and the Huntsman.
Horror movie The Pact enters the top ten at number four, while Avengers completes the top five. Joss Whedon's superhero ensemble has now earned more than £50 million in the UK, making it the highest-grossing movie of the year so far.
Elsewhere, Ben Drew's directorial debut iLL Manors makes its chart bow at number nine. The gritty East London-set drama pulls in more than £250,000 from its 191 locations.
George Lucas's Red Tails fails to dent the top ten, making £193,420 from 226 cinemas to land at number 11.
The UK box office top ten in full:
1. (1) Prometheus - £3,135,504
2. (3) Men in Black III - £2,533,051
3. (2) Snow White and the Huntsman - £2,210,929
4. (-) The Pact - £932,325
5. (4) Marvel Avengers Assemble - £676,678
6. (7) Top Cat: The Movie - £561,793
7. (5) The Dictator - £452,175
8. (6) What to Expect When You're Expecting - £445,141
9. (-) iLL Manors - £256,288
10. (9) The Angels' Share - £218,674
Watch the stars of Prometheus discuss the movie with Digital Spy below: