LOS ANGELES, Feb. 18 -- Marvel and Disney's new superhero film Captain America: Brave New World easily dominated the North American box office this weekend, earning an estimated US$100 million in the biggest opening of the year, industry watcher Exhibitor Relations reported Sunday.

The film's strong showing on a four-day US holiday weekend came despite tepid reviews and lukewarm audience scores, with analysts saying stories of superhero-movie fatigue may be exaggerated.

Anthony Mackie stars as Sam Wilson, taking over the title role from Chris Evans, this time in a tale about an international struggle over a cache of super-powerful adamantium. Harrison Ford plays a US president who (spoiler alert) morphs into a monster.

Columbia and Sony'...