'Cloverfield' has become the first monster hit of 2008 after making $41m (€28m) in the US last weekend, a record opening for January according to studio estimates.
Watch an extended clip from 'Cloverfield' here.
The tale of a giant reptile causing chaos in New York City surpassed the $35.9m premiere weekend of the 'Star Wars' special edition in 1997, the previous best for January.
Featuring a cast of unknowns, 'Cloverfield' tells its monster story from the perspective of a partygoer's hand-held video camera, which captures the mayhem as the creature tears through the city.
The film benefited from cryptic marketing that sent moviegoers on a scavenger hunt to decode clues about the movie's plot, images and even its title, which was not confirmed until shortly before its release.
'Cloverfield' is released in Ireland on 1 February.