The Hangover Part II tops US box office
Directed by Todd Philips, The Hangover Part II reunites many of the cast members of the original comedy, including Bradley Cooper, Zach Galifianakis, Justin Bartha and Ed Helms.
It tells of a group of friends who head to Thailand for a wedding, only for things to go awry.
Kung Fu Panda 2, featuring the voices of Jack Black, Angelina Jolie and Jackie Chan, debuted at two, while last week's number one, Pirates of the Caribbean: On Stranger Tides, slipped to three.
Bridesmaid dropped from two to four, while Thor and Fast Five also slipped two places, taking the fifth and sixth positions respectively.
Midnight in Paris, Woody Allen's latest film, was the only other new entry in the chart. Starring Owen Wilson, Rachel McAdams and Kathy Bates, it opened at seven.
Jumping the Broom, Something Borrowed and Rio rounded off the top ten.