The Bourne Ultimatum is the third in the series

The film, starring Matt Damon as former assassin Jason Bourne, took �2.2m to keep comedy Knocked Up in second place with �1.42m.

Fantasy horror 1408 was the highest new entry at three with receipts of �1.07m, while The Simpsons movie stayed at four with �0.62m.

Rush Hour 3 dropped two places to number five, taking �0.56m.

UK AND IRELAND BOX OFFICE 1. The Bourne Ultimatum (�2.23m) 2. Knocked Up (�1.43m) 3. 1408 (�1.07m) 4. The Simpsons Movie (�0.62m) 5. Rush Hour 3 (�0.56m) 6. No Reservations (�0.41m) 7. Harry Potter And The Order Of The Phoenix (�0.39m) 8. Transformers (�0.32m) 9. Bratz: The Movie (�0.32m) 10. Death Sentence (�0.26m) Source: Screen International

Catherine Zeta Jones' kitchen-based comedy cooked up a top 10 entry at six, with Harry Potter and the Order of the Phoenix being nudged down two places.

Placed at number seven, the film's UK box office haul now stands at �48.5m.

Family film Transformers dropped two positions to eight, while Bratz the Movie, based on the popular series of dolls, sank from seven to nine.

Rounding off the top 10 was new entry Death Sentence, a thriller starring Kevin Bacon and Kelly Preston.