Washington, July 28 : Christian Bale and the late Heath Ledger continued to reign at the box office with their Batman movie 'The Dark Knight' raking in 75.6 million dollars at the box office over the weekend.
Studio estimates show that The Dark Knight's second-weekend gross was the biggest ever, and it is now being predicted that it will bash the 400 million dollar mark in the 18 days after its release.
Second highest grossing over the weekend was 'Step Brothers' which raked in 30 million dollars.
Pierce Brosnan, Colin Firth musical 'Mamma Mia!' came in at the third spot, taking in 17.9 million dollars.
David Duchovny and Gillian Anderson's return to the big screen in 'The X-Files: I Want to Believe' however disappointed with an earning of only 10.2 million dollars in its debut weekend.
The top five was rounded off by the big screen adaptation of Jules Vernes classic 'Journey to the Center of the Earth' starring Brendan Fraser, which took in 9.4 million dollars, reports E!Online.
The list for the top-grossing weekend films based on Friday-Sunday estimates compiled by Exhibitor Relations is:
1. The Dark Knight, USD75.6m
2. Step Brothers, USD 30m
3. Mamma Mia!, USD 17.9m
4. The X-Files: I Want to Believe, USD 10.2m
5. Journey to the Center of the Earth, USD 9.4m
6. Hancock, USD 8.2m
7. WALL-E, USD 6.3m
8. Hellboy II: The Golden Army, USD 4.9m
9. Space Chimps, USD 4.4m
10. Wanted, USD 2.7m