'Thor: The Dark World' hammers competition to open at No.1 in US THOR: The Dark World, earning $US86.1 million ($91.7 million), has dominated the weekend box office in the US as it opened at No.1, according to studio estimates. The Marvel superhero sequel, which earned $US109.4 million when it opened globally last weekend, brought in $US180.1 million worldwide. Hidden-camera comedy Jackass Presents: Bad Grandpa held the second place slot for the second weekend in a row, earning $11.3 million during its third weekend, with a US total reaching more than $US78 million. 3-D animated kiddie flick Free Birds soared into third place with $US11.1 million in its second weekend at the box office.