Ginormica (right) is voiced by actress Reese Witherspoon
Animated adventure Monsters vs. Aliens has scored the biggest US box office debut of the year so far with takings of $58.2m (£41m).
The Dreamworks film, which sees classic movie monsters pitted against beings from outer space, beat ghost story The Haunting In Connecticut into second.
The animation, which features the voice of Reece Witherspoon, saw the weekend's ticket sales up 39% compared to 2008.
Cinema sales in 2009 are beating the recession, according to analysts.
"The recession offers a framework from which movies can do well for people looking to escape," said Paul Dergarabedian, head of Media By Numbers, which tracks US box office performance.
US BOX OFFICE TOP FIVE
Monsters vs. Aliens - $58.2m
The Haunting in Connecticut - $23m
Knowing - $14.7m
I Love You, Man - $12.6m
Duplicity - $7.6m
Source: Media By Numbers
"But they have to want to escape to these movies. The appeal has to be there, and it clearly was for Monsters vs. Aliens," he added.
The movie, which also features the voices of Kiefer Sutherland and Seth Rogan, has also been offered in 3D format which has proved popular.
While the enhanced version was offered in only 28% of screens, it accounted for more than 55% of its box office revenues with a slightly more expensive ticket price.
Monsters vs. Aliens' number one debut was way ahead of its nearest rival, The Haunting in Connecticut, which took $23m ($16.2m).
Last week's chart topper, Knowing, starring Nicolas Cage, slipped to number three on the chart.